annual surveillance report january 2018 through … safety...annual surveillance report january 2018...

Prepared By:

GENTERRA Consultants, Inc.15375 Barranca Pkwy, Bldg L

Irvine, CA 92618www.genterra.com

Tel: (949) 753-8766Fax: (949) 753-8887

Annual Surveillance ReportJanuary 2018 through December 2018

Sand Canyon DamDSOD Dam No. 1029-002

Irvine, CAJune 14, 2019

Prepared For:

Irvine Ranch Water DistrictField Operations Department

P. O. Box 57000Irvine, CA 92619-7000

ANNUAL SURVEILLANCE REPORT JANUARY 2018 THROUGH DECEMBER 2018

SAND CANYON DAM, DSOD DAM NO. 1029-002

397B-IRW_Sand Cyn Dam-Annual Rpt 2018_FINAL.doc i GENTERRA Consultants, Inc.

TABLE OF CONTENTS

SECTION 1: INTRODUCTION AND BACKGROUND ........................................................ 1

1.1 GENERAL ........................................................................................................................ 1

1.2 DAM AND RESERVOIR ................................................................................................. 1

1.3 SPILLWAY ....................................................................................................................... 2

1.4 OUTLET WORKS ............................................................................................................ 2

1.5 SUBDRAINS .................................................................................................................... 3

SECTION 2: FIELD MEASUREMENTS ................................................................................. 4

2.1 GENERAL ........................................................................................................................ 4

2.2 PIEZOMETERS ................................................................................................................ 4

2.3 SUBDRAIN FLOWS ........................................................................................................ 8

2.4 MOVEMENT SURVEYS ................................................................................................. 9

SECTION 3: FIELD EVALUATIONS .................................................................................... 11

3.1 FIELD EVALUATION OF MAY 2, 2018 ...................................................................... 11

3.1.1 DAM .................................................................................................................... 11

3.1.2 SPILLWAY ......................................................................................................... 11

3.1.3 OUTLET WORKS .............................................................................................. 12

3.1.4 SEEPAGE ........................................................................................................... 12

3.2 FIELD EVALUATION OF DECEMBER 20, 2018 ........................................................ 13

3.2.1 DAM .................................................................................................................... 13

3.2.2 SPILLWAY ......................................................................................................... 13

3.2.3 OUTLET WORKS .............................................................................................. 14

3.2.4 SEEPAGE ........................................................................................................... 14

SECTION 4: CONCLUSIONS AND RECOMMENDATIONS ........................................... 15

4.1 CONCLUSIONS ............................................................................................................. 15

4.2 RECOMMENDATIONS ................................................................................................ 15

SECTION 5: LIMITATIONS ................................................................................................... 17

SECTION 6: REFERENCES ................................................................................................... 18



397B-IRW_Sand Cyn Dam-Annual Rpt 2018_FINAL.doc ii GENTERRA Consultants, Inc.

TABLE OF CONTENTS (Continued) TABLES Table 1 Piezometer and Subdrain Measurements,

January 2009 through December 2018

Table 2 Horizontal Offset of Survey Monuments Relative to Original Baseline, 1975 through 2018

Table 3 Net Horizontal Displacement of Survey Monuments, 1975 through 2018

Table 4 Elevations of Survey Monuments, 1975 through 2018

Table 5 Net Vertical Movement of Survey Monuments, 1975 through 2018

FIGURES Figure 1 Site and Instrumentation Plan

Figure 2 Section A-A’

Figure 3 Section B-B’

Figure 4A 2-Yr Piezometer and Reservoir Water Surface Elevations, Piezometers P-1A, P-1B, and P-6, January 2017 through December 2018

Figure 4B 2-Yr Piezometer and Reservoir Water Surface Elevations, Piezometers P-2A, P-2B, P-5, P-10A, and P-10B, January 2017 through December 2018

Figure 4C 2-Yr Piezometer and Reservoir Water Surface Elevations, Piezometers P-4, P-8A, P-8B, P-9A, P-9B, and P-11, January 2017 through December 2018

Figure 4D 2-Yr Piezometer and Reservoir Water Surface Elevations, Piezometers P-3 and P-7, January 2017 through December 2018

Figure 4E 2-Yr Piezometer and Reservoir Water Surface Elevations, Piezometers P-12 and P-13, January 2017 through December 2018

Figure 5A 10-Yr Historical Piezometer and Reservoir Water Surface Elevations, Piezometers P-1A, P-1B, and P-6, January 2009 through December 2018



397B-IRW_Sand Cyn Dam-Annual Rpt 2018_FINAL.doc iii GENTERRA Consultants, Inc.

TABLE OF CONTENTS (Continued) Figure 5B 10-Yr Historical Piezometer and Reservoir Water Surface Elevations,

Piezometers P-2A, P-2B, P-5, P-10A, and P-10B, January 2009 through December 2018

Figure 5C 10-Yr Historical Piezometer and Reservoir Water Surface Elevations, Piezometers P-4, P-8A, P-8B, P-9A, P-9B, and P-11, January 2009 through December 2018

Figure 5D 10-Yr Historical Piezometer and Reservoir Water Surface Elevations, Piezometers P-3 and P-7, January 2009 through December 2018

Figure 5E 10-Yr Historical Piezometer and Reservoir Water Surface Elevations, Piezometers P-12 and P-13, January 2009 through December 2018

Figure 6 2-Yr Seepage Flow Rates and Reservoir Water Surface Elevations, January 2017 through December 2018

Figure 7 10-Yr Historical Seepage Flow Rates and Reservoir Water Surface Elevations, January 2009 through December 2018

Figure 8 24-Yr Historical Net Horizontal Displacement, Survey Monuments S-1 through S-6, January 1995 through December 2018

Figure 9 24-Yr Historical Net Vertical Movement, Survey Monuments S-1 through S-6, January 1995 through December 2018



397B-IRW_Sand Cyn Dam-Annual Rpt 2018_FINAL.doc 1 GENTERRA Consultants, Inc.

SECTION 1: INTRODUCTION AND BACKGROUND 1.1 GENERAL

This report presents the results of the dam safety monitoring and surveillance program for Sand Canyon Dam conducted by the Irvine Ranch Water District (District) and GENTERRA Consultants, Inc. (GENTERRA) for the 12-month period from January 2018 through December 2018. It includes a compilation of the field measurements, observations, and conclusions related to the general condition and safety of the dam. In addition, recommendations are provided for continued operation, surveillance, and monitoring of the dam. This report is submitted as part of the jurisdictional requirements of the State of California, Department of Water Resources, Division of Safety of Dams (DSOD).

The tables provided in this report present field measurements of piezometer water levels, reservoir water surface elevations, seepage flow rates, and net horizontal and net vertical movement based on survey data collected at Sand Canyon Dam. Graphs illustrating piezometer water levels and seepage flow rates, each with corresponding reservoir water surface elevations are provided for the two-year period (January 2017 through December 2018), as well as for the 10-year period (January 2009 through December 2018). The 10-year plots are included to show longer-term trends, to facilitate evaluation of the performance of the dam and reservoir, and to more easily identify any adverse trends or significant deviations in the data. Tables 2 through 5 present the results of horizontal and vertical movement surveys from 1975 through 2018. Graphs of the net horizontal displacement and net vertical movement for the 24-year period from 1995 through 2018 are shown on Figures 8 and 9, respectively.

1.2 DAM AND RESERVOIR

Sand Canyon Dam is a compacted earthfill embankment dam located on Sand Canyon Wash in Irvine, California. The dam was completed in 1942. The District took over operation of the Sand Canyon Dam and Reservoir in 1967 from The Irvine Company.

The vertical datum used for the dam safety monitoring program is the National Geodetic Vertical Datum of 1929 (NGVD29).

Modifications to the dam have occurred over the years. The current configuration of the dam consists of the following: the crest of the dam is at Elevation 202 feet, and there is a one-foot-high concrete parapet wall along the upstream edge of the crest of the dam (Figure 1). The downstream edge of the crest of the dam has a small curb. The height of the dam is 58 feet with a crest length of 861 feet and a crest width of 10 feet. Asphalt Concrete (AC) covers the crest of the dam.

The upstream face of the dam is lined with 3-inch-thick AC extending approximately 19 feet down from the upstream edge of the crest of the dam and has a slope gradient of 2.5H:1V (Horizontal: Vertical). The downstream face of the dam is covered with grass and has a slope gradient of 2H:1V. No benches were constructed on either face of the dam.




The dam was designed as a zoned embankment with an upstream zone consisting of “selected impervious” material, a central zone of “random” material, and a downstream zone of “unselected pervious” material (Figures 2 and 3). During construction of the dam, test results indicated that the embankment is fairly homogeneous and consists, for the most part, of medium dense sandy clay and clayey sand (DSOD, 1984). The dam is reported as being founded on alluvium across the original broad stream channel, and on the sandstone of the Santiago Formation near the abutments.

A cutoff trench was constructed under portions of the upstream and central zones of embankment material (see Figure 2). The trench typically penetrates 2 to 4 feet into the sandstone bedrock but does not extend across the full width of the broad alluvial channel.

The reservoir has a drainage area of about 6.8 square miles. Per the document titled “Dams within the Jurisdiction of the State of California” (DSOD, 2000) the reservoir has a storage capacity of 960 acre-feet. However, because of modifications and many years of sediment accumulation, the storage capacity has been reduced to approximately 768 acre-feet (AECOM, 2016).

1.3 SPILLWAY

Located on the right abutment, the spillway consists of an approach channel, an ungated ogee weir, and a rectangular-shaped spillway channel. The spillway channel has reinforced concrete retaining walls on both sides, with a maximum height of 18 feet. The bottom of the channel is mostly unlined and consists of sandstone bedrock with filled-in areas of dental concrete. The channel conveys the water to an energy dissipation structure that outlets to Sand Canyon Wash. The spillway crest is at Elevation 193.5 feet, which provides 8.5 feet of freeboard (not counting the one-foot high parapet wall along the upstream edge of the dam crest).

1.4 OUTLET WORKS

The outlet works have been modified over the years and are currently controlled by four upstream gates and three downstream valves. The outlet works consist of a 36-inch-diameter ungated corrugated metal pipe (CMP) with an inlet at Elevation 187.0 feet. The 36-inch-diameter pipe has three 24-inch-diameter inlet slide gates at Elevations 169.9, 177.1, and 185.0 feet, and one 20-inch-diameter main gate located near the upstream toe. The inlet gates are manually operated from the controls located at the upstream edge of the crest of the dam. Per the operating procedures posted on the controls, at least one of the 24-inch-diameter inlet gates is to remain fully open at all times when it is below the reservoir level. The main gate is to remain fully open at all reservoir levels except during temporary periods for maintenance shutdown.

The 20-inch-diameter steel outlet pipe is 260 feet in length and transitions to a 24-inch-diameter distribution line near the toe of the dam. A 16-inch-diameter gate valve is located between the 20-inch and 24-inch lines. The 24-inch-diameter distribution line has a 24-inch-diameter gate valve about 100 feet downstream of the toe of the dam. Just upstream of the 24-inch gate valve, the 24-inch line splits to a 20-inch-diameter outfall line. At approximately 330 feet downstream of the toe of the dam, the 24-inch line has a 24-inch-diameter butterfly blow off valve and nearby splits again




to a 24-inch-diameter outfall line. The 20-inch outfall line connects to the 24-inch outfall line and transitions to a 30-inch-diameter outfall line that discharges to Sand Canyon Wash (Figure 1).

1.5 SUBDRAINS

No internal drains were installed during the construction of the dam. However, two seepage subdrains referred to as the Left Subdrain and Right Subdrain, were installed at the downstream toe near the left groin (Figure 1). The Left Subdrain consists of a 6-inch pipe with two 4-inch branches, and the Right Subdrain is a 6-inch pipe extending approximately 100 feet parallel to the toe (DSOD, 1984). The two subdrains discharge into a Drain Junction Vault.




SECTION 2: FIELD MEASUREMENTS 2.1 GENERAL

There are 18 open-well piezometers, two seepage subdrains, and six survey monuments being monitored at Sand Canyon Dam. District personnel measure the water levels in the piezometers and reservoir, and seepage flow rates from the two drains monthly and immediately following significant seismic events. The survey monuments are surveyed annually by a licensed surveyor under contract with the District. Precipitation is measured at an on-site rain gage.

Figure 1 is a site and instrumentation plan showing the layout of the dam and appurtenances, as well as the locations of the piezometers, seepage collection subdrains, and survey monuments. Figures 2 and 3 show Sections A-A’ and B-B’, respectively. Section A-A’ is at the approximate location of the deepest portion of the alluvium in the foundation. Section B-B’ is at approximate the location of the maximum section of the dam. As used in this report, the left and right designations are as viewed looking downstream.

During the 12-month review period, the reservoir water surface elevation varied from a minimum elevation of 177.3 feet to a maximum elevation of 184.3 feet (about 18 feet below the dam crest). The reservoir elevations that were read on the same dates as the instrumentation are shown in Table 1.

An abandoned weir is located downstream of the dam on the left abutment adjacent to the golf cart path. Intermittent flow from this weir is occasionally observed but is not measured by the District.

2.2 PIEZOMETERS

A piezometer is a small diameter well used mainly to measure water levels. It is typically installed as a casing in a vertical borehole and has a discrete perforated zone near its bottom to enable monitoring of changes in groundwater levels within that zone. More than one piezometer can be installed within a single, larger-diameter outer well casing. These groups of piezometers are often referred to as multi-stage or nested piezometers. The tip of each piezometer is generally placed at its own discrete depth range within the outer well casing. The outer well casing is perforated along the vertical zones corresponding to the depths of the piezometer tips.

There are 18 piezometers currently being monitored at Sand Canyon Dam. At this facility, there are five nested piezometers, Piezometers P-1, P-2, P-8, P-9, and P-10, each having two piezometers in them, designated as A and B.

The water levels in the piezometers are measured monthly by the District. The reservoir water surface elevation is also noted at the time of the field measurements. The location of each piezometer is shown on Figure 1. Thirteen of the 18 piezometers are located either at or near the maximum depth of foundation alluvium (Section A-A’ on Figure 2), or at the section near the maximum section of the dam (Section B-B’ on Figure 3). Three of the remaining five piezometers are in the right portion of the dam and two are in the left portion. On Sections A-A’ and B-B’




(Figures 2 and 3), for the selected piezometers, the maximum historical water levels since 1984 are shown along with the maximum and minimum piezometer water levels recorded during the 12-month review period (January 2018 through December 2018).

Table 1 provides the reservoir water surface elevation and piezometer water levels for the 10-year period from January 2009 through December 2018. Figures 4A through 4E are graphical plots of piezometer water levels and reservoir water surface elevations during the two-year period from January 2017 through December 2018. Figures 5A through 5E are graphical plots that cover a 10-year period from January 2009 through December 2018.

In December 2015, the District converted Piezometers P-9A, P-9B, P-10A, P-10B, P-11, P-12, and P-13 to vibrating wire piezometers. A vibrating wire piezometer contains a high tensile steel wire attached at one end to a diaphragm. The wire is electronically plucked to make it vibrate, and its resonant frequency is proportional to the tension in the wire. The frequency of vibration in the wire induces an alternating electrical current in a coil. The magnitude of the current is detected, and the reading is then converted to a pressure. The pressure fluctuates with changes in water levels in the immediate vicinity of the piezometer tip.

The following is a summary of the water level measurements taken during the 12-month review period for each piezometer and a discussion of the historical trends and any questionable or erroneous measurements that were noted.

Piezometers P-1A, P-1B, and P-6 are located in the right portion of the dam. Piezometer P-1A is nested in the same well as Piezometer P-1B on the crest of the dam, while Piezometer P-6 is near the toe. The tip of Piezometer P-1A is located within the dam embankment downstream from the cutoff trench, while Piezometers P-1B and P-6 have tips within the foundation alluvium. Graphs of the water levels during the two-year period from January 2017 through December 2018 are shown on Figure 4A, and those for a 10-year historical period from January 2009 through December 2018 are shown on Figure 5A. Piezometer P-1A has historically shown little to no response to reservoir water surface fluctuations and the water levels tend to stay within a small range. A reading taken on June 28, 2016 is below the reported bottom of the piezometer and is therefore considered as erroneous. During the 12-month review period, the water levels in P-1A remained fairly consistent. Piezometers P-1B and P-6 respond to reservoir water surface fluctuations and the range during the 12-month review period was within the historical water levels. Fluctuations in these two piezometers appear to indicate that water levels within the alluvium do show some response to changes in reservoir water levels.

Piezometers P-2A, P-2B, P-5, P-10A, and P-10B are located at or near the section of the dam overlying the maximum depth of the foundation alluvium (Section A-A’ on Figure 2). Piezometer P-2A is nested in the same well as Piezometer P-2B and they are situated on the crest of the dam. During July through September 2017 period, water level in P-2A was temporarily higher than the water surface elevation of the reservoir. This temporary condition occurred because, during the period starting from April to July 2017, the elevation of the reservoir water surface had been lowered




by 30 feet. This is a significant drawdown over a three-month period and this time period did not allow the high pore pressure that had been developed during high reservoir water level to dissipate quickly enough to stay below the reservoir water level. That is nothing unusual for an earth embankment dam during a significant drawdown period. Readings taken on September 27 and October 24, 2018 are reported below the bottom of Piezometer 2A and are therefore considered as erroneous. Piezometer P-5 is situated near the toe of the dam. Piezometer P-10A is nested in the same well as Piezometer P-10B and they are situated along the downstream face of the dam. Graphs of the water levels measured during the two-year period from January 2017 through December 2018 are shown on Figure 4B, and those for a 10-year historical period from January 2009 through December 2018 are shown on Figure 5B.

Piezometers P-2A and P-10A are installed in the dam embankment, and generally respond to reservoir water surface fluctuations. A reading of the water level in Piezometer P-2A taken on April 4, 2010 showed a sudden increase, followed by the water level readings returning to below Elevation 173 feet. This single measurement is likely erroneous. A reading taken on May 23, 2017 in Piezometer P-10A showed a sudden decrease, followed by higher water level readings. This single measurement is likely erroneous. The water levels observed in these piezometers during this 12-month review period were consistent with historical levels.

Piezometers P-2B, P-5, and P-10B are installed in the foundation alluvium. Piezometers P-2B and P-10B show little response to reservoir water surface fluctuations, while Piezometer P-5 shows very little if any correlation. Readings taken on October 29, 2013, August 26, 2014, March 26, 2015, April 29, 2015, August 26, 2015, and November 24, 2015 in Piezometer P-10B indicated sudden increases in the water level in that piezometer. Following those high readings however, the water level returned to below Elevation 140 feet. Therefore, those measurements were likely erroneous. The water levels observed in these piezometers during this 12-month review period were generally consistent with historical levels.

Piezometers P-4, P-8A, P-8B, P-9A, P-9B, and P-11 are located at the maximum section of the dam (see Section B-B’ on Figure 3). Piezometer P-8A is nested in the same well as Piezometer P-8B and they are situated on the crest of the dam. Piezometer P-4 is situated near the toe of the dam. Piezometer P-9A is nested in the same well as Piezometer P-9B and they are situated along the downstream face of the dam approximately in-line with Piezometer P-11. Graphs of the water levels during the two-year period from January 2017 through December 2018 are shown on Figure 4C, and those for a 10-year historical period from January 2009 through December 2018 are shown on Figure 5C.

Piezometers P-8A, P-9A, and P-11 are installed in the dam embankment. Piezometers P-8A and P-9A generally respond to reservoir water surface fluctuations, while Piezometer P-11 shows very little response. A reading taken on October 26, 2017 was approximately 27 feet below the reported bottom of Piezometer P-11, and a reading taken on June 28, 2018 was approximately 16 feet below the reported bottom of the piezometer. Therefore, those readings were considered as erroneous. The




water levels observed in these piezometers during this 12-month review period were generally consistent with historical levels.

Piezometers P-4 and P-8B are installed in foundation bedrock, and P-9B is installed in foundation alluvium. Piezometers P-8B and P-9B generally respond to reservoir water surface fluctuations, while increases and decreases in Piezometer P-4 may be related to rainwater. On August 26, 2014, a sudden decrease to a dry reading was reported in Piezometer P-9B, followed by water level readings returning to Elevation 155 feet. This single measurement is likely erroneous. The water levels observed in these piezometers during this 12-month review period were consistent with historical levels.

Piezometers P-3 and P-7 are located in the left portion of the dam. Piezometer P-3 is situated on the crest of the dam while Piezometer P-7 is on the downstream face near the left groin. Graphs of the water levels during the two-year period from January 2017 through December 2018are shown on Figure 4D, and those for a 10-year historical period from January 2009 through December 2018 are shown on Figure 5D. The tips of these piezometers are believed to be set below the base of the embankment, and possibly into bedrock. During the July through August 2017 period, water level in P-3 was temporarily higher than the water surface elevation of the reservoir. This temporary condition occurred because during the period starting from April to July 2017, the elevation of the reservoir water surface had been lowered by 30 feet. This is a significant drawdown over a three-month period and this time period did not allow the high pore pressure that was developed during high reservoir water level to dissipate quick enough to stay below the reservoir water level, this is nothing unusual for an earth embankment dam during significant drawdown period. During the 12-month review period and historically, Piezometer P-7 has shown relatively high water levels considering that it is located near the downstream toe of the dam. Since the cutoff trench and the alluvium in the foundation are not believed to extend this far to the left, it is likely that a semi-pervious zone on top of the bedrock remains in place beneath this portion of the dam. If present, such a zone would account for much of the seepage that is intercepted by the Left Subdrain (see Section 2.3). Based on historical data, these two piezometers generally respond to reservoir water surface fluctuations, but Piezometer P-7 generally becomes dry when the reservoir water surface remains below an elevation of approximately 170 feet. A questionable reading taken on September 28, 2011 in Piezometer P-3 indicated a sudden increase in the water level. Following the high reading however, the water level returned to below Elevation 170 feet. This single measurement was likely erroneous. The water levels observed in these piezometers during this 12-month review period were generally consistent with historical levels.

Piezometers P-12 and P-13 are located on the downstream face of the dam near the toe between Sections A-A’ and B-B’. Graphs of the water levels during the two-year period from January 2017 through December 2018 are shown on Figure 4E, and those for a 10-year historical period from January 2009 through December 2018 are shown on Figure 5E. The tip elevation of these two piezometers is believed to be in the dam embankment. Water levels observed in these piezometers show some response to reservoir water surface fluctuations, and they are at about the same elevation (approximately 153 feet) as that of the invert of the Right Subdrain. On October 26, 2010, a dry




reading was reported in Piezometer P-12 that corresponds to a water level approximately 2 feet above the reported bottom of the piezometer. This reading is considered as erroneous. A reading taken on August 29, 2012 was below the reported bottom elevation of the piezometer and was therefore considered as erroneous. The water levels observed in these piezometers during this 12-month review period were consistent with historical levels.

Based on GENTERRA’s review of the piezometer data, there are no indications of any adverse conditions in the dam embankment, abutments, or foundation. The District should have the elevations of tops of casings surveyed and should measure the depth to the bottom of each piezometer periodically to verify that the casings are not blocked to their entire as-built depth, and to confirm the elevation of the bottom of the piezometer. The District should continue to closely monitor the water levels in each piezometer.

2.3 SUBDRAIN FLOWS

No internal drains were installed during construction of the dam. Because of seepage appearing at the downstream toe soon after the reservoir first began to be filled with water, a seepage collection drain (Left Subdrain) was installed in the left groin near the downstream toe. Modifications occurred over the years and in 1976, a second seepage collection subdrain (Right Subdrain) was added. The Left Subdrain consists of a 6-inch-diameter pipe with two 4-inch-diameter branches, and the Right Subdrain is a 6-inch-diameter pipe extending approximately 100 feet parallel to the toe (DSOD, 1984). The two subdrains discharge into the Drain Junction Vault, which is located at the downstream toe of the dam near the left abutment (Figure 1). An outlet pipe from the Drain Junction Vault then discharges the seepage flow to a drop inlet structure. The flow rates of the two subdrains discharging into the Drain Junction Vault are measured by District personnel on a monthly basis.

A graph on Figure 6 presents the seepage flow rates from the Left and Right Subdrains versus the reservoir water surface elevations for the two-year period from January 2017 through December 2018. The graph on Figure 7 covers a 10-year period from January 2009 through December 2018. Tabulated data for the 10-year period are presented in Table 1.

On March 24, 2016, GENTERRA was called to inspect an area of seepage observed upstream of the seepage collection vault located at the downstream toe, near the left side of the dam. Observations and a summary of concerns were sent to the District by GENTERRA. Using suggestions by GENTERRA, an investigation was then performed by the District to determine the cause for this seepage. It was determined that the pipe for the seepage collection drain had become blocked by roots and soil, and several portions of the pipe had been damaged. The roots and soil were then removed from the pipe by the District and the pipe was repaired, a cap was installed on the upstream end, and a liner was placed along the portions that had cracked. GENTERRA reviewed a copy of the District’s video recording showing the repaired areas in the seepage drain.

Repairs of the Left Subdrain were performed at two different times in the past. One of the repairs was made in 1999 following the discovery of a sinkhole near the left abutment in October 1999, and the other was the repair in 2016 after the discovery of a broken pipe (described above). The graph




on Figure 7 shows that the seepage flow rate through the Left Subdrain tends to increase when the reservoir water surface is above an elevation of approximately 180 feet. The flow rate then decreases to less than 0.5 gallons per minute (gpm) when the reservoir water surface remains below Elevation 180 feet. As noted in Section 2.2 of this report, it is likely that a semi-pervious zone on top of the bedrock remains in place beneath the left portion of the dam. If present, such a zone would account for much of the seepage that is intercepted by the Left Subdrain. The flows should continue to be observed for clarity to check for the presence of any suspended solids that might indicate a potential piping condition.

During this 12-month review period, the Right Subdrain was dry, and the Left Subdrain flow rate ranged from no flow from August through November 2018, to a maximum flow rate of 0.29 gpm on April 27, 2018. Based on historical data, the maximum flow rate of 3.96 gpm was measured from the Left Subdrain on June 28, 2000. Based on GENTERRA’s review of the subdrain data, the flow rates appear to be consistent with historical flow rates and there are no indications of any adverse conditions.

2.4 MOVEMENT SURVEYS

A total of six survey monuments (S-1 through S-6) are being surveyed at Sand Canyon Dam. All six survey monuments are located on the crest of the dam spanning from left abutment to right abutment (Figure 1). Survey Monuments S-1 through S-5 were initially read on September 15, 1975, while S-6 was initially read on October 20, 1987. According to AECOM (2016), historical survey data was located for the years 1975, 1981, and 1982 in a DSOD Safety Review Report dated April 1984. It should be noted that there is a data gap of about 33 years from the date the dam was constructed in 1942 to the initial survey beginning in 1975.

The survey monuments are usually surveyed annually by a licensed surveyor under contract with the District. Bush & Associates, Inc. performed the last survey of the survey monuments on May 31, 2018. No survey was performed during the year 2017.

Table 2 presents the horizontal Offset of Survey Monuments relative to their original baseline alignment, whereas Table 3 presents the net horizontal displacement of the survey monuments. Table 4 presents the actual elevations of the survey monuments, whereas Table 5 presents the net vertical movement of the survey monuments. Tables 2 through 5 cover a date range from 1975 through 2018. Figures 8 and 9 are graphical plots of the net horizontal displacement and net vertical movement of survey monuments from January 1995 through December 2018, respectively. Since no survey was performed in 2017, there is no data entered for 2017 in the tables or graphs for horizontal or vertical movement.

A comparison of the most recent survey data (2018) with the 2016 data indicates that the largest horizontal movement was 0.01 foot (0.12 inch) in the downstream direction at Survey Monument S-5 (Table 2). Survey Monuments S-1, S-3, and S-6 did not exhibit any change in horizontal movement during the same two-year period.




As illustrated on Figure 8, the net horizontal displacement data indicate minor fluctuations in the movement in both the upstream and downstream direction since 1995. As of 2018, the maximum net horizontal displacement in the downstream direction was 0.065 foot (0.78 inch) at Survey Monuments S-3 and S-4, and 0.025 foot (0.30 inch) in the upstream direction at Survey Monument S-6 (Table 3).

The data indicate a maximum uplift/heave of 0.27 foot (3.24 inches) recorded at Survey Monument S-4 on May 28, 1997. Comparison of the most recent survey data (2018) with the previous (2016) data indicate that the largest vertical change was an uplift/heave of 0.015 foot (0.18 inch) at Survey Monuments S-5 and S-6 (Table 5). As of 2018, the maximum cumulative vertical movement was an uplift/heave of 0.252 foot (3.024 inches) at Survey Monument S-4 (Table 5).

Based on GENTERRA’s review of the survey data, the horizontal and vertical displacements of survey monuments appear to be minimal and consistent with historical surveys. There are no indications of any adverse conditions as determined from data obtained through 2018.




SECTION 3: FIELD EVALUATIONS 3.1 FIELD EVALUATION OF MAY 2, 2018

A field evaluation of Sand Canyon Dam on May 2, 2018 was performed by Douglas A. Harriman, P.E. and J. Will Kulikowski of GENTERRA; Steve Habiger and Tyler Dillman of the District; Philip Lee of DSOD was also present. The reservoir water surface was at an elevation of 184.1 feet at the time of the field evaluation. Photographs were taken and are in the project files at GENTERRA for comparison with previous and future inspections.

3.1.1 DAM

The crest of the dam is surfaced with asphalt concrete (AC) pavement and was in satisfactory condition at the time of this field evaluation, with no signs of settlement, instability, or significant cracking. Minor surficial longitudinal cracking was observed in the AC along the downstream portion of the crest of the dam, but it is not considered to be significant. The parapet wall along the upstream edge of the crest of the dam was in good condition at the time of this field evaluation.

The upper portion of the upstream face of the dam is paved with AC and was in satisfactory condition. The lower portion of the upstream slope is not paved and was not visible due to the reservoir level. During the previous field evaluation dated December 28, 2017, minor cracking was observed throughout the AC on the upstream face of the dam. Repairs had been made but it was observed during the field evaluation that some cracks were still present. This minor cracking should continue to be monitored in the future and plans for patching and repair should be made if the cracking worsens. There were no signs of settlement or instability.

The downstream face of the dam is covered with grass and was in satisfactory condition. The vegetation on the downstream slope was trimmed and was at a satisfactory height. DSOD noted in January 1984 that the downstream slope has an uneven appearance and concluded that it was not a dam safety hazard (AECOM, 2016). There were no significant signs of cracking or instability on the slope.

The rodent abatement program for the dam is ongoing and appears to be working satisfactorily.

3.1.2 SPILLWAY

The spillway approach, ogee weir, channel, and energy dissipator were in satisfactory condition. The reservoir water surface was more than nine feet below the spillway crest elevation. Minor seepage was observed at the left edge, central portion, and right edge just downstream of the spillway crest. Vegetation is growing in the natural channel (Sand Canyon Wash) just downstream of the energy dissipator. Note that any vegetation in the natural channel downstream of the energy dissipator may impact the performance of the spillway.




3.1.3 OUTLET WORKS

DSOD recommends that the outlet and the emergency blow-off valves be exercised and documented in a log at least once per year to confirm operability. DSOD requires the valves be exercised once every three years in the presence of a DSOD representative.

The outlet works are currently controlled by four upstream gates and three downstream valves. The 36-inch-diameter CMP inlet, the three 24-inch-diameter outlet gates (Nos. 1, 2, and 3), and the 20-inch-diameter main gate were under water at the time of this field evaluation. The controls for the outlet valves are located at the upstream edge of the crest of the dam and appeared to be in satisfactory condition. The three upstream outlet gates were exercised through a full cycle and in the presence of the DSOD representative on May 2, 2018. On May 26, 2016, the main gate was attempted to be cycled, but broke as it was being closed. At the time of this field evaluation on May 2, 2018, the District had completed the repair of the main gate.

In 2016, exploratory excavation work was performed by the District to uncover the 30-inch-diameter blowoff valve. GENTERRA estimated the locations of the outlet works (valves and lines) as shown on Figure 1. GENTERRA recommends an updated survey to create a site plan that will show current layout of features at the project site as well as the locations of all lines and valves of the outlet works.

There are two 24-inch-diameter emergency blow-off valves located downstream of the dam. These two valves are located in-line so that one can be kept close while the other one is exercised, which minimizes the release of water. Both valves were exercised through a full cycle in the presence of the DSOD representative during this field evaluation.

On the date of a previous field evaluation on December 28, 2017, the District had completed the in-kind replacement of the main gate valve and no problems have been reported or were observed.

3.1.4 SEEPAGE

Seepage flow rates are measured monthly by District personnel in the Drain Junction Vault located at the downstream toe of the dam near the left groin. A small amount of seepage flow was observed from the Left Subdrain. The Right Subdrain was dry.

A small amount of seepage was observed at the abandoned weir located downstream of the dam on the left abutment adjacent to the golf cart path. The District observes but does not measure the seepage flow rate from this weir. The history, purpose, and significance of this weir are not known.

The area of seepage observed during the previous field evaluation around the abandoned weir located downstream of the dam on the left abutment adjacent to the golf cart path, had dried up.




3.2 FIELD EVALUATION OF DECEMBER 20, 2018

A field evaluation of Sand Canyon Dam on December 20, 2018 was performed by Soma Balachandran, Ph.D., G.E., P.E. and J. Will Kulikowski of GENTERRA; and Bill Wesson of the District. The reservoir water surface was at an elevation of 176.2 feet at the time of the field evaluation. Photographs were taken and are in the project files at GENTERRA for comparison with previous and future inspections.

3.2.1 DAM

The crest of the dam is surfaced with asphalt concrete (AC) pavement and was in satisfactory condition, with no signs of settlement, instability, or significant cracking. Previous field evaluations noted minor cracking on the crest of the dam. During this field evaluation, it was observed that a slurry seal had been placed on the entire paved portion of the crest. Minor cracking is still present. The parapet wall along the upstream edge of the crest of the dam appeared to be in good condition, but minor vegetation growth was observed along the base of the parapet wall.

The upper portion of the upstream face of the dam is paved with AC and was in satisfactory condition, but minor vegetation growth was observed along existing cracks. The lower portion of the upstream slope is not paved, and the visible portion appeared to be in good condition. Previous field evaluations noted minor cracking on the upstream slope. During this field evaluation, it was observed that a slurry seal had been placed on the entire paved portion of the upstream slope. Minor cracking is still present. This minor cracking should continue to be monitored in the future and plans for patching and repair should be made if the cracking worsens. There were no signs of settlement or instability. Vegetation growth along the existing cracks should be controlled.

The downstream face of the dam has some uneven slope at some locations and is covered with grass and was in satisfactory condition, but a few erosion gullies were observed near the left abutment. The vegetation on the downstream slope was at a satisfactory height. DSOD noted in January 1984 that the downstream slope has an uneven appearance and concluded that it was not a dam safety hazard (AECOM, 2016). There were no significant signs of cracking or instability on the slope. There was a minor amount of recent rodent activity observed on the downstream face near the downstream toe area, left abutment area, and near downstream edge of dam crest in the form of fresh burrows. GENTERRA recommends the District continue to improve their rodent abatement program. Some maintenance repair is needed for the access ramp located in the left abutment. Also, vegetation control should be improved near the left abutment. All erosion gullies should be repaired.

3.2.2 SPILLWAY

The spillway approach, ogee weir, channel, and energy dissipator were in satisfactory condition. The spillway approach was dry. Vegetation was observed in the energy dissipator structure at its downstream end. GENTERRA recommends periodic removal of vegetation from the energy dissipator so that the energy dissipator can perform as intended during the design. Heavy vegetation is growing in the natural channel (Sand Canyon Wash) just downstream of the energy dissipator.




Note that any vegetation in the natural channel downstream of the energy dissipator may impact the performance of the spillway.

3.2.3 OUTLET WORKS

The outlet works are currently controlled by four upstream gates and three downstream valves. The 36-inch-diameter CMP and one of the three 24-inch-diameter outlet gates (No. 3) was above the water surface and appeared to be in good condition. The controls for the outlet valves are located at the upstream edge of the crest of the dam and appeared to be in satisfactory condition. During this field evaluation, none of the outlet valves or blowoff valves were exercised.

3.2.4 SEEPAGE

Seepage flow rates are measured monthly by District personnel in the Drain Junction Vault located at the downstream toe of the dam near the left groin. There was no flow observed from either the Left or Right Subdrains.




SECTION 4: CONCLUSIONS AND RECOMMENDATIONS 4.1 CONCLUSIONS

4.1.1 Based on the available data, the dam appears to be performing satisfactorily.

4.1.2 The piezometers exhibited water levels that are generally consistent with historical values and trends. Piezometer P-12 (on October 26, 2010) had a dry reading at an elevation above the reported tip elevation at the bottom of the piezometer. Piezometers P-1A (on June 28, 2016), P-2A (on September 27 and October 24, 2018), P-9A (on July 26, 2018), P-11 (on October 26, 2017 and June 28, 2018), and P-12 (on August 29, 2012) had readings reported below their reported tip elevations. The reported tip elevations of Piezometers P-1A, P-2A, P-9A, P-11, and P-12 are 159.3 feet, 153.9 feet, 160.4 feet, 155.4 feet, and 151.5 feet, respectively.

4.1.3 Horizontal and vertical movement of the survey monuments appears to be normal and consistent with historical values and trends, as determined by survey data through 2018.

4.1.4 Minor cracking was observed on the dam crest and upstream face of the dam. A slurry seal had recently been placed on both of these surfaces. Vegetation along existing cracks should be controlled.

4.1.5 Minor rodent activity was observed on the downstream face of the dam at several locations, such as downstream toe area, area near the left abutment, and area near the downstream edge of the dam crest.

4.1.6 Vegetation was observed in the energy dissipator structure at its downstream end. Heavy vegetation is growing in the natural channel just downstream of the energy dissipator.

4.1.7 The three outlet gates (Nos. 1, 2, and 3) were exercised through a full cycle in the presence of a DSOD representative on May 2, 2018. On May 26, 2016, the main gate was attempted to be cycled, but it broke as it was being closed. The two blow-off valves located downstream of the dam were last exercised through a full cycle in the presence of a DSOD representative on May 2, 2018.

4.1.8 GENTERRA had estimated the locations of the outlet works (valves and lines) as shown on Figure 1.

4.2 RECOMMENDATIONS

4.2.1 The District should have the elevations of the top of piezometer casings surveyed and the depth to bottom of each piezometer is measured at the same time as surveying to determine the tip elevation of each piezometer. Also, the District should measure the




depth to the bottom of each piezometer periodically to verify that the casings are not blocked to their entire as-built depth, and to confirm the elevation of the bottom of the piezometer. It is also beneficial to physically mark the depth of each piezometer tip on the piezometer cover to check the validity of water level readings or dry readings immediately after the measurements are taken.

4.2.2 The District should monitor the areas where cracks are present. Any increase in cracking of the AC surfaces should be reported to a District supervisor and the District’s Dam Safety Consultant.

4.2.3 The District should continue the on going program for controlling rodent activity.

4.2.4 The District should repair the existing erosion gullies that were observed on the downstream face near the left abutment of the dam as well as any other erosion gullies that may have developed recently. Also, it is beneficial to regrade the downstream slope to get rid of uneven spots and to provide a condition that will allow easy and timely detection of any developing issue on the downstream slope.

4.2.5 The District should remove vegetation that is growing in the natural channel just downstream of the energy dissipator.

4.2.6 During the daily, weekly, and monthly operations at the dam, District personnel should always be observing the condition of the dam, appurtenances, and other features in the immediate area around the dam, looking for signs of distress or movement, increased seepage, or other unusual conditions, and verifying that the critical facilities are functional. Any unusual observations should be reported immediately to a District supervisor and the District’s Dam Safety Consultant under contract at the time.

4.2.7 GENTERRA recommends the District should continue to perform a special evaluation of the dam immediately after any earthquake with a Magnitude of 4.5 or greater within a 50-mile radius of the dam, and/or any seismic event that would cause heavy furniture overturning in areas in the vicinity of the dam and reservoir.




SECTION 5: LIMITATIONS This report represents the results of our surveillance program for Sand Canyon Dam, covering the period from January 2018 through December 2018. Professional services were provided to evaluate the performance of the existing dam based upon review of previous data, field inspections, instrumentation readings, and surveys.

The conclusions and professional opinions presented herein were developed by GENTERRA Consultants, Inc. for the Irvine Ranch Water District in accordance with generally accepted engineering principles and practices. We make no other warranty, either express or implied.




SECTION 6: REFERENCES

1. AECOM, 2016, 2015 Annual Surveillance Report for Sand Canyon Dam, DSOD Dam No. 1029-002, Orange County, California; by AECOM; dated April 21, 2016.

2. AECOM, 2015, 2014 Annual Surveillance Report for Sand Canyon Dam, DSOD Dam No. 1029-002, Orange County, California; by AECOM; dated May 22, 2015.

3. California Department of Water Resources, Division of Safety of Dams (DSOD), 2018, Dams Within Jurisdiction of the State of California, by DSOD; dated September 2018.

4. California Department of Water Resources, Division of Safety of Dams (DSOD), 2000, Dams Within Jurisdiction of the State of California, Bulletin 17-00; by DSOD; dated July 2000.

5. California Department of Water Resources, Division of Safety of Dams (DSOD), 1984, Sand Canyon Dam, 1029-2, Safety Review Report; by DSOD; dated April 1984.

6. GENTERRA Consultants, Inc., 2018, Annual Surveillance Report, January 2017 through December 2017 for Sand Canyon Dam and Reservoir, DSOD Dam No. 1029-002, Irvine, California; by GENTERRA; dated November 26, 2018

7. GENTERRA Consultants, Inc., 2017, Annual Surveillance Report, January 2016 through December 2016 for Sand Canyon Dam and Reservoir, DSOD Dam No. 1029-002, Irvine, California; by GENTERRA; dated August 25, 2017.

8. GENTERRA Consultants, Inc., 2013, Annual Surveillance Report, January 2012 through December 2012 for Sand Canyon Dam and Reservoir, No. 1029-2, Irvine, California; by GENTERRA; dated March 18, 2013.

9. GENTERRA Consultants, Inc., 2012, Annual Surveillance Report, January 2011 through December 2011 for Sand Canyon Dam and Reservoir, No. 1029-2, Irvine, California; by GENTERRA; dated May 10, 2012.

10. GENTERRA Consultants, Inc., 2011, Annual Surveillance Report, January 2010 through December 2010 for Sand Canyon Dam and Reservoir, No. 1029-2, Irvine, California; by GENTERRA; dated May 18, 2011.

11. GENTERRA Consultants, Inc., 2004, Annual Surveillance Report, July 2003 through June 2004, for Sand Canyon Dam and Reservoir, No.1029-2, Irvine, California; by GENTERRA Consultants, Inc.; dated September 28, 2004.

12. URS Corporation, 2014, 2013 Annual Surveillance Report for Sand Canyon Dam, DSOD Dam No. 1029-002, Orange County, California; by URS; dated June 30, 2014.

13. URS Corporation, 2010, 2009 Annual Surveillance Report for Sand Canyon Dam, DSOD Dam No. 1029-002, Orange County, California; by URS; dated July 2010.



397B-IRW_Sand Cyn Dam-Annual Rpt 2018_FINAL.doc GENTERRA Consultants, Inc.

TABLES

Project No. 397B-IRW TABLE 1SAND CANYON DAM

PIEZOMETER AND SUBDRAIN MEASUREMENTSJANUARY 2009 THROUGH DECEMBER 2018

GENTERRA Consultants, Inc.

201.9 201.8 201.9 202.0159.3 132.9 153.9 123.8

42.6 68.9 48.0 78.2Reservoir

Date Elevation Rainfall Reading Elev. Comment Reading Elev. Comment Reading Elev. Comment Reading Elev. Comment(ft) (in.) (ft) (ft) (ft) (ft) (ft) (ft) (ft) (ft)

Piezometer No. →Top Elevation (ft) →Tip Elevation (ft) →Depth (ft) →

P-1A P-1B P-2A P-2B

1/29/2009 182.20 0.39 42.4 159.5 57.5 144.3 34.8 167.1 61.3 140.72/25/2009 185.70 3.10 42.0 159.9 57.0 144.8 34.1 167.8 59.9 142.13/26/2009 188.40 0.10 42.4 159.5 56.9 144.9 33.2 168.7 61.0 141.04/28/2009 189.30 0.00 42.4 159.5 56.7 145.1 32.0 169.9 61.3 140.75/18/2009 188.50 0.00 41.3 160.6 56.6 145.2 31.4 170.5 61.0 141.05/27/2009 188.10 0.00 42.2 159.7 56.7 145.1 31.2 170.7 61.0 141.06/30/2009 188.60 0.10 42.4 159.5 56.7 145.1 31.2 170.7 61.3 140.77/30/2009 184.80 0.00 42.3 159.6 56.9 144.9 30.9 171.0 61.3 140.78/26/2009 176.60 0.00 41.5 160.4 57.8 144.0 31.6 170.3 61.8 140.29/30/2009 174.50 0.00 42.2 159.7 59.0 142.8 33.3 168.6 62.8 139.2

10/28/2009 175.30 0.29 42.6 159.3 59.2 142.6 34.2 167.7 63.0 139.012/1/2009 176.40 0.00 42.0 159.9 59.4 142.4 35.2 166.7 63.3 138.7

12/28/2009 178.80 2.75 42.5 159.5 58.6 143.3 35.5 166.5 62.2 139.81/26/2010 191.30 4.15 42.4 159.5 57.3 144.5 34.9 167.0 60.6 141.42/24/2010 193.60 2.29 42.4 159.5 55.4 146.4 32.5 169.4 59.8 142.23/29/2010 193.50 1.18 42.2 159.7 55.4 146.4 29.9 172.0 60.0 142.0

4/4/2010 193.50 41.5 160.4 55.5 146.3 25.5 176.4 Erroneous 60.0 142.04/27/2010 193.90 1.66 42.3 159.6 55.4 146.4 29.2 172.7 59.9 142.15/27/2010 192.90 0.03 41.4 160.5 55.4 146.4 28.7 173.2 59.9 142.16/29/2010 191.60 0.00 41.4 160.5 55.4 146.4 28.7 173.2 59.7 142.37/28/2010 187.50 0.00 42.3 159.6 55.9 145.9 29.1 172.8 60.4 141.68/31/2010 179.20 0.00 41.5 160.4 57.3 144.5 30.8 171.1 61.4 140.69/29/2010 175.60 0.00 41.2 160.7 58.5 143.3 31.7 170.2 62.0 140.0

10/26/2010 178.20 2.93 41.4 160.5 58.6 143.2 33.0 168.9 61.9 140.111/30/2010 178.80 1.14 42.6 159.3 58.8 143.0 34.4 167.5 62.4 139.612/30/2010 193.90 9.95 42.4 159.5 55.4 146.4 33.8 168.1 59.5 142.5

1/27/2011 194.00 0.86 41.5 160.4 55.4 146.4 30.4 171.5 60.0 142.02/23/2011 193.80 1.02 42.4 159.5 55.5 146.4 28.9 173.0 59.7 142.33/29/2011 193.90 2.38 41.3 160.6 54.9 146.9 28.1 173.8 59.5 142.54/27/2011 193.60 0.56 42.3 159.6 55.3 146.5 27.6 174.3 59.8 142.25/25/2011 193.10 0.51 41.4 160.5 55.2 146.6 27.9 174.0 59.8 142.26/28/2011 192.00 0.00 42.3 159.6 55.3 146.5 28.2 173.7 59.7 142.3

Notes:Elevations are in feet relative to NGVD29 datum;Elev. = Elevation; ft = feet; in. = inches IRVINE RANCH WATER DISTRICT Page 1 of 20




201.9 201.8 201.9 202.0159.3 132.9 153.9 123.8

42.6 68.9 48.0 78.2Reservoir



P-1A P-1B P-2A P-2B

7/27/2011 186.75 0.00 41.5 160.5 55.8 146.0 28.9 173.1 60.0 142.08/25/2011 176.30 0.00 42.4 159.5 57.2 144.6 30.3 171.6 61.0 141.09/28/2011 176.00 0.06 42.4 159.5 58.6 143.3 32.5 169.5 62.1 139.9

10/25/2011 176.50 0.89 42.2 159.7 59.1 142.7 33.5 168.4 62.3 139.711/22/2011 177.20 1.31 42.4 159.5 58.9 143.0 34.4 167.5 62.2 139.812/22/2011 176.70 0.20 41.6 160.3 59.0 142.8 34.5 167.4 62.5 139.5

1/25/2012 178.60 0.84 41.4 160.5 58.6 143.2 35.0 166.9 61.9 140.12/28/2012 179.20 0.68 41.5 160.4 58.6 143.2 35.5 166.4 61.1 140.93/27/2012 180.60 1.73 41.5 160.4 58.4 143.5 35.1 166.8 61.6 140.46/27/2012 180.70 0.00 42.5 159.4 58.6 143.2 33.8 168.1 61.9 140.17/26/2012 179.20 0.10 42.3 159.6 58.7 143.1 34.3 167.6 62.1 139.9

8/8/2012 178.50 0.10 42.2 159.7 58.9 142.9 34.3 167.6 62.7 139.38/28/2012 177.10 0.00 42.4 159.5 59.3 142.5 34.6 167.3 62.9 139.18/29/2012 177.10 0.00 42.0 159.9 59.1 142.7 34.3 167.6 62.7 139.39/25/2012 175.30 0.00 42.3 159.6 59.8 142.0 35.0 166.9 63.5 138.5

10/30/2012 176.00 0.19 42.3 159.6 60.0 141.8 35.6 166.3 63.8 138.211/27/2012 175.80 0.69 42.4 159.5 59.7 142.1 35.8 166.2 63.4 138.612/12/2012 176.10 0.70 42.5 159.4 59.7 142.1 35.7 166.2 62.9 139.1

1/22/2013 177.20 1.40 42.4 159.5 58.8 143.0 36.0 165.9 62.1 139.92/27/2013 178.20 1.20 42.3 159.6 58.4 143.4 35.8 166.1 61.8 140.23/28/2013 178.20 0.31 42.4 159.5 58.4 143.4 35.8 166.1 61.7 140.34/25/2013 177.30 0.71 42.5 159.4 58.4 143.4 35.9 166.0 62.4 139.75/22/2013 177.60 0.03 42.5 159.4 59.0 142.8 35.9 166.0 62.3 139.76/25/2013 177.50 0.00 42.3 159.6 59.2 142.7 36.0 165.9 62.5 139.57/23/2013 175.70 0.00 42.5 159.4 59.6 142.2 36.0 165.9 63.1 138.98/21/2013 174.50 0.00 42.5 159.4 59.9 141.9 36.2 165.7 63.7 138.39/25/2013 175.70 0.00 42.6 159.3 60.2 141.6 36.3 165.6 63.8 138.2

10/29/2013 176.00 0.00 42.6 159.3 59.9 141.9 36.5 165.4 63.6 138.411/27/2013 176.50 0.44 42.3 159.6 59.5 142.3 36.4 165.5 63.3 138.712/19/2013 176.80 0.53 42.5 159.4 59.5 142.3 36.4 165.5 63.1 138.9





201.9 201.8 201.9 202.0159.3 132.9 153.9 123.8

42.6 68.9 48.0 78.2Reservoir



P-1A P-1B P-2A P-2B

1/28/2014 176.80 0.00 42.5 159.4 59.1 142.7 36.5 165.4 62.7 139.32/25/2014 176.70 0.72 42.3 159.6 59.0 142.8 36.6 165.3 62.5 139.53/25/2014 178.50 42.5 159.4 58.5 143.3 36.5 165.4 62.0 140.03/29/2014 178.40 1.44 42.5 159.4 58.6 143.2 36.6 165.3 62.0 140.04/25/2014 177.40 0.74 42.4 159.5 58.8 143.0 36.3 165.6 62.2 139.85/28/2014 176.40 0.00 42.5 159.4 59.4 142.4 36.3 165.6 62.9 139.16/25/2014 176.10 0.00 42.5 159.4 60.0 141.8 36.5 165.4 63.6 138.47/30/2014 177.30 0.00 42.5 159.4 60.1 141.7 36.4 165.5 63.7 138.48/26/2014 176.10 0.03 42.5 159.4 60.2 141.6 36.3 165.6 63.8 138.29/23/2014 175.90 0.00 42.3 159.6 60.3 141.5 36.5 165.4 64.2 137.9

10/30/2014 176.30 0.00 42.2 159.7 60.1 141.7 36.6 165.3 64.0 138.011/21/2014 176.20 0.25 42.2 159.7 59.9 141.9 36.7 165.2 63.9 138.112/30/2014 178.90 3.37 42.3 159.6 58.8 143.0 36.7 165.2 62.5 139.5

1/27/2015 179.60 0.89 42.3 159.6 58.3 143.5 36.2 165.7 62.2 139.92/27/2015 180.00 0.46 42.3 159.6 58.3 143.5 35.8 166.1 62.0 140.03/26/2015 179.60 0.45 42.3 159.6 58.2 143.6 35.7 166.2 62.1 139.94/29/2015 178.20 0.24 42.2 159.7 58.7 143.1 35.5 166.4 62.7 139.35/27/2015 179.00 1.04 42.2 159.7 58.6 143.2 35.8 166.1 62.6 139.46/25/2015 179.60 0.00 42.2 159.7 58.5 143.3 35.6 166.3 62.3 139.77/29/2015 178.10 0.00 42.3 159.6 58.9 142.9 35.5 166.4 63.1 138.98/26/2015 176.20 0.00 42.2 159.7 59.2 142.6 35.4 166.5 63.3 138.79/22/2015 178.20 1.64 42.2 159.7 58.9 142.9 35.8 166.1 62.8 139.2

10/27/2015 176.90 0.10 42.3 159.6 59.0 142.8 35.8 166.1 63.0 139.011/24/2015 176.30 0.17 42.2 159.7 59.2 142.6 36.0 165.9 63.1 138.912/22/2015 177.60 0.72 42.3 159.7 58.9 143.0 36.1 165.8 62.9 139.1

1/27/2016 180.10 2.86 42.6 159.3 58.2 143.6 36.5 165.4 61.9 140.12/25/2016 181.60 0.20 42.2 159.7 57.8 144.0 35.6 166.3 61.8 140.23/24/2016 184.80 1.48 42.3 159.6 57.7 144.1 34.1 167.8 61.3 140.73/31/2016 184.50 1.51 42.2 159.7 57.7 144.1 35.0 166.9 61.8 140.24/28/2016 183.60 0.04 42.2 159.7 57.8 144.0 34.3 167.7 62.1 139.95/25/2016 182.50 0.13 42.2 159.7 58.0 143.8 34.2 167.7 62.2 139.86/28/2016 180.70 0.00 42.9 159.0 Erroneous 59.2 142.6 33.3 168.6 63.3 138.7





201.9 201.8 201.9 202.0159.3 132.9 153.9 123.8

42.6 68.9 48.0 78.2Reservoir



P-1A P-1B P-2A P-2B

7/27/2016 178.40 0.00 42.4 159.5 59.1 142.7 34.2 167.7 63.1 138.98/24/2016 176.40 0.00 42.3 159.6 59.6 142.3 34.8 167.1 63.5 138.59/27/2016 175.80 0.00 42.3 159.6 60.0 141.8 35.3 166.6 63.9 138.1

10/26/2016 178.60 0.64 42.3 159.6 59.8 142.0 35.6 166.3 63.7 138.311/22/2016 178.30 1.11 42.4 159.5 59.7 142.1 35.5 166.4 63.5 138.512/28/2016 184.80 4.01 42.3 159.6 59.0 142.8 35.6 166.3 62.6 139.4

1/25/2017 193.30 6.33 42.4 159.5 56.1 145.7 34.6 167.3 59.0 143.02/28/2017 193.90 3.27 42.3 159.6 54.5 147.3 31.2 170.7 58.8 143.23/29/2017 193.70 0.08 42.4 159.5 54.7 147.1 29.6 172.3 59.2 142.84/27/2017 192.90 0.04 42.2 159.7 54.7 147.1 28.8 173.1 59.5 142.55/23/2017 187.90 0.33 42.2 159.7 55.2 146.6 29.1 172.8 59.5 142.56/21/2017 182.50 0.00 42.2 159.7 56.1 145.7 29.9 172.0 60.1 141.97/26/2017 163.60 0.00 42.2 159.7 58.2 143.6 32.0 169.9 61.6 140.48/30/2017 163.60 0.00 42.2 159.7 59.7 142.1 34.1 167.8 62.9 139.19/28/2017 163.60 0.00 42.3 159.6 60.8 141.0 35.5 166.4 63.7 138.3

10/26/2017 171.80 0.00 42.1 159.8 61.4 140.4 36.2 165.7 64.2 137.811/29/2017 177.20 0.08 42.2 159.7 60.7 141.1 36.8 165.1 64.4 137.612/27/2017 176.70 0.00 42.3 159.6 Dry 60.9 140.9 36.4 165.5 64.5 137.5

1/24/2018 178.10 1.67 42.3 159.6 Dry 60.3 141.5 36.0 165.9 63.9 138.12/21/2018 177.80 0.27 42.2 159.7 60.2 141.6 35.9 166.0 63.9 138.13/28/2018 183.50 1.23 42.3 159.6 Wet 59.7 142.1 35.6 166.3 63.5 138.54/27/2018 184.30 0.05 42.2 159.7 59.5 142.3 35.0 166.9 63.5 138.55/30/2018 183.10 0.13 42.2 159.7 59.1 142.7 34.0 167.9 63.4 138.66/28/2018 181.70 0.00 42.4 159.5 59.3 142.5 33.8 168.1 63.6 138.47/26/2018 180.00 0.00 42.4 159.5 59.8 142.0 34.2 167.7 63.6 138.48/28/2018 177.30 0.00 42.3 159.6 60.2 141.6 34.3 167.6 64.2 137.89/27/2018 178.10 0.00 42.3 159.6 60.3 141.5 64.4 137.5 Erroneous 64.7 137.3

10/24/2018 178.00 0.66 42.4 159.5 60.3 141.5 64.4 137.5 Erroneous 64.3 137.711/29/2018 177.50 1.60 42.3 159.6 60.3 141.5 35.0 166.9 64.3 137.712/20/2018 181.40 2.39 42.2 159.7 59.1 142.7 35.0 166.9 62.9 139.1





ReservoirDate Elevation Rainfall

(ft) (in.)


1/29/2009 182.20 0.392/25/2009 185.70 3.103/26/2009 188.40 0.104/28/2009 189.30 0.005/18/2009 188.50 0.005/27/2009 188.10 0.006/30/2009 188.60 0.107/30/2009 184.80 0.008/26/2009 176.60 0.009/30/2009 174.50 0.00

10/28/2009 175.30 0.2912/1/2009 176.40 0.00

12/28/2009 178.80 2.751/26/2010 191.30 4.152/24/2010 193.60 2.293/29/2010 193.50 1.18

4/4/2010 193.504/27/2010 193.90 1.665/27/2010 192.90 0.036/29/2010 191.60 0.007/28/2010 187.50 0.008/31/2010 179.20 0.009/29/2010 175.60 0.00

10/26/2010 178.20 2.9311/30/2010 178.80 1.1412/30/2010 193.90 9.95

1/27/2011 194.00 0.862/23/2011 193.80 1.023/29/2011 193.90 2.384/27/2011 193.60 0.565/25/2011 193.10 0.516/28/2011 192.00 0.00

201.2 150.7 151.5 167.4155.8 129.1 129.6 127.7

45.4 21.6 21.9 39.7

Reading Elev. Comment Reading Elev. Comment Reading Elev. Comment Reading Elev. Comment(ft) (ft) (ft) (ft) (ft) (ft) (ft) (ft)

P-6P-3 P-4 P-5

27.1 174.1 10.9 139.8 9.1 142.4 24.0 143.425.1 176.1 10.8 139.9 9.1 142.4 23.5 143.923.3 177.9 10.8 139.9 9.2 142.3 23.4 144.022.4 178.8 10.9 139.8 9.1 142.4 23.1 144.322.8 178.4 10.9 139.8 9.2 142.3 23.2 144.223.0 178.2 10.9 139.8 9.2 142.3 23.2 144.222.8 178.4 11.0 139.7 9.0 142.5 23.7 143.724.7 176.5 11.0 139.7 9.1 142.4 23.4 144.029.2 172.0 11.1 139.6 9.1 142.4 24.2 143.232.1 169.1 11.3 139.4 9.2 142.3 25.3 142.131.8 169.4 11.5 139.2 8.3 143.2 25.6 141.831.5 169.7 11.9 138.8 9.5 142.0 25.7 141.729.9 171.3 11.3 139.4 9.5 142.0 24.9 142.522.8 178.4 9.9 140.8 9.2 142.3 23.8 143.620.3 180.9 9.8 140.9 7.9 143.6 22.0 145.419.7 181.5 8.5 142.2 8.2 143.3 22.0 145.419.8 181.4 8.7 142.0 8.2 143.3 22.1 145.319.5 181.7 8.9 141.8 7.8 143.7 22.0 145.419.9 181.3 9.2 141.5 7.8 143.7 22.0 145.420.6 180.6 9.5 141.2 7.7 143.8 22.0 145.422.6 178.6 9.8 140.9 7.8 143.7 22.4 145.027.9 173.3 10.2 140.5 8.0 143.5 23.6 143.831.2 170.0 10.6 140.1 8.1 143.4 24.9 142.530.5 170.7 10.8 139.9 9.7 141.8 24.9 142.530.2 171.0 11.6 139.1 8.3 143.2 25.0 142.420.4 180.8 8.6 142.1 5.9 145.6 22.0 145.420.0 181.2 9.3 141.4 6.2 145.4 22.0 145.420.0 181.3 9.5 141.2 5.9 145.6 22.0 145.419.6 181.6 8.9 141.8 6.7 144.8 21.7 145.719.7 181.5 9.0 141.7 7.0 144.5 22.0 145.420.2 181.0 9.2 141.5 7.0 144.5 21.9 145.520.7 180.5 9.3 141.4 7.2 144.3 22.0 145.4






(ft) (in.)


7/27/2011 186.75 0.008/25/2011 176.30 0.009/28/2011 176.00 0.06

10/25/2011 176.50 0.8911/22/2011 177.20 1.3112/22/2011 176.70 0.20

1/25/2012 178.60 0.842/28/2012 179.20 0.683/27/2012 180.60 1.736/27/2012 180.70 0.007/26/2012 179.20 0.10

8/8/2012 178.50 0.108/28/2012 177.10 0.008/29/2012 177.10 0.009/25/2012 175.30 0.00

10/30/2012 176.00 0.1911/27/2012 175.80 0.6912/12/2012 176.10 0.70

1/22/2013 177.20 1.402/27/2013 178.20 1.203/28/2013 178.20 0.314/25/2013 177.30 0.715/22/2013 177.60 0.036/25/2013 177.50 0.007/23/2013 175.70 0.008/21/2013 174.50 0.009/25/2013 175.70 0.00

10/29/2013 176.00 0.0011/27/2013 176.50 0.4412/19/2013 176.80 0.53

201.2 150.7 151.5 167.4155.8 129.1 129.6 127.7

45.4 21.6 21.9 39.7


P-6P-3 P-4 P-5

23.5 177.8 9.4 141.4 7.1 144.4 22.4 145.029.7 171.5 9.7 141.0 7.2 144.3 23.6 143.824.7 176.5 Erroneous 10.5 140.3 7.6 143.9 24.9 142.531.7 169.5 11.0 139.7 8.1 143.4 25.2 142.231.7 169.6 11.1 139.7 8.2 143.4 25.2 142.231.7 169.5 11.5 139.2 8.2 143.3 25.4 142.030.8 170.4 11.7 139.0 8.3 143.2 25.0 142.430.5 170.7 11.7 139.0 8.5 143.0 25.0 142.429.7 171.5 11.5 139.2 8.4 143.1 24.8 142.728.0 173.2 10.3 140.4 8.8 142.7 24.9 142.529.8 171.5 10.9 139.8 8.8 142.7 25.1 142.330.1 171.1 10.8 139.9 8.6 142.9 25.3 142.131.0 170.2 11.2 139.5 8.7 142.8 26.6 140.830.8 170.4 11.0 139.7 8.5 143.0 25.5 141.932.2 169.0 11.6 139.1 8.8 142.7 26.1 141.332.0 169.2 12.1 138.6 8.9 142.6 26.3 141.132.2 169.0 12.4 138.3 9.4 142.1 26.0 141.431.9 169.3 12.5 138.2 9.5 142.0 25.8 141.631.3 169.9 12.5 138.2 9.6 141.9 25.1 142.330.7 170.5 12.2 138.5 9.3 142.2 24.7 142.731.0 170.2 12.1 138.6 9.5 142.0 24.7 142.731.6 169.6 12.2 138.6 9.6 141.9 25.1 142.331.4 169.8 12.1 138.6 9.6 141.9 25.3 142.131.4 169.9 12.2 138.6 9.6 141.9 25.5 142.032.4 168.8 12.3 138.4 9.7 141.8 25.9 141.532.8 168.4 12.5 138.2 9.7 141.8 26.3 141.132.4 168.8 12.9 137.8 10.2 141.3 26.5 140.932.2 169.0 13.0 137.7 10.2 141.3 26.3 141.231.8 169.4 12.9 137.8 10.0 141.5 25.9 141.531.7 169.5 13.1 137.6 10.2 141.3 25.8 141.6






(ft) (in.)


1/28/2014 176.80 0.002/25/2014 176.70 0.723/25/2014 178.503/29/2014 178.40 1.444/25/2014 177.40 0.745/28/2014 176.40 0.006/25/2014 176.10 0.007/30/2014 177.30 0.008/26/2014 176.10 0.039/23/2014 175.90 0.00

10/30/2014 176.30 0.0011/21/2014 176.20 0.2512/30/2014 178.90 3.37

1/27/2015 179.60 0.892/27/2015 180.00 0.463/26/2015 179.60 0.454/29/2015 178.20 0.245/27/2015 179.00 1.046/25/2015 179.60 0.007/29/2015 178.10 0.008/26/2015 176.20 0.009/22/2015 178.20 1.64

10/27/2015 176.90 0.1011/24/2015 176.30 0.1712/22/2015 177.60 0.72

1/27/2016 180.10 2.862/25/2016 181.60 0.203/24/2016 184.80 1.483/31/2016 184.50 1.514/28/2016 183.60 0.045/25/2016 182.50 0.136/28/2016 180.70 0.00

201.2 150.7 151.5 167.4155.8 129.1 129.6 127.7

45.4 21.6 21.9 39.7


P-6P-3 P-4 P-5

32.0 169.2 13.0 137.7 10.3 141.2 25.5 141.932.2 169.0 12.8 137.9 10.3 141.2 25.4 142.130.9 170.3 8.1 142.6 10.2 141.3 24.9 142.531.1 170.1 8.2 142.5 10.3 141.2 24.9 142.531.5 169.7 8.9 141.8 10.2 141.3 25.0 142.432.4 168.8 9.7 141.0 10.3 141.3 25.7 141.732.2 169.0 10.3 140.4 10.2 141.3 26.3 141.131.6 169.6 10.7 140.1 10.2 141.3 26.4 141.032.1 169.1 11.0 139.7 10.2 141.3 26.4 141.032.0 169.2 11.4 139.3 10.3 141.2 26.7 140.832.1 169.1 11.9 138.8 10.5 141.0 26.5 140.931.8 169.4 12.1 138.6 10.5 141.0 26.2 141.230.3 170.9 11.9 138.8 10.5 141.0 25.2 142.229.9 171.3 11.9 138.8 10.5 141.1 24.8 142.629.7 171.5 11.9 138.8 10.5 141.0 24.6 142.830.0 171.2 11.9 138.8 10.4 141.1 24.5 142.930.8 170.4 11.9 138.8 10.6 140.9 24.9 142.530.8 170.4 12.0 138.7 10.4 141.1 24.9 142.529.8 171.4 12.0 138.7 10.3 141.2 25.0 142.430.8 170.4 12.3 138.4 10.4 141.1 25.3 142.131.9 169.3 12.3 138.4 10.4 141.1 25.6 141.831.0 170.2 9.3 141.4 10.5 141.0 25.3 142.131.4 169.8 9.9 140.8 10.5 141.0 25.3 142.132.5 168.7 10.4 140.3 10.6 140.9 25.7 141.731.2 170.0 10.7 140.0 10.5 141.0 25.2 142.230.2 171.0 10.2 140.5 10.5 141.0 24.5 142.929.2 172.0 10.6 140.1 9.9 141.6 24.2 143.227.6 173.6 10.1 140.6 9.8 141.7 24.0 143.427.6 173.6 10.2 140.5 9.8 141.7 24.1 143.327.8 173.4 10.4 140.3 9.8 141.7 24.3 143.128.4 172.8 10.6 140.1 9.8 141.7 24.4 143.029.3 171.9 11.0 139.7 9.9 141.6 24.9 142.5






(ft) (in.)


7/27/2016 178.40 0.008/24/2016 176.40 0.009/27/2016 175.80 0.00

10/26/2016 178.60 0.6411/22/2016 178.30 1.1112/28/2016 184.80 4.01

1/25/2017 193.30 6.332/28/2017 193.90 3.273/29/2017 193.70 0.084/27/2017 192.90 0.045/23/2017 187.90 0.336/21/2017 182.50 0.007/26/2017 163.60 0.008/30/2017 163.60 0.009/28/2017 163.60 0.00

10/26/2017 171.80 0.0011/29/2017 177.20 0.0812/27/2017 176.70 0.00

1/24/2018 178.10 1.672/21/2018 177.80 0.273/28/2018 183.50 1.234/27/2018 184.30 0.055/30/2018 183.10 0.136/28/2018 181.70 0.007/26/2018 180.00 0.008/28/2018 177.30 0.009/27/2018 178.10 0.00

10/24/2018 178.00 0.6611/29/2018 177.50 1.6012/20/2018 181.40 2.39

201.2 150.7 151.5 167.4155.8 129.1 129.6 127.7

45.4 21.6 21.9 39.7


P-6P-3 P-4 P-5

30.7 170.5 11.1 139.6 9.9 141.6 25.5 141.932.1 169.2 11.4 139.3 10.0 141.5 25.6 141.832.7 168.5 11.8 138.9 10.1 141.4 26.4 141.031.0 170.2 11.2 139.5 10.2 141.3 25.4 142.031.2 170.0 12.2 138.5 10.3 141.3 26.1 141.329.3 172.0 12.3 138.4 10.3 141.2 25.5 142.022.5 178.7 11.0 139.7 7.1 144.4 22.6 144.821.4 179.8 9.3 141.4 6.7 144.8 21.1 146.321.2 180.0 9.1 141.6 7.2 144.3 21.4 146.021.5 179.7 9.0 141.7 7.2 144.3 21.4 146.023.8 177.4 9.1 141.6 7.3 144.2 21.9 145.527.0 174.2 9.3 141.4 7.3 144.2 22.6 144.834.6 166.6 9.7 141.0 8.3 143.3 24.4 143.037.8 163.4 10.5 140.2 7.2 144.3 25.9 141.540.2 161.0 11.4 139.3 10.5 141.0 26.9 140.541.4 159.8 11.7 139.0 10.6 140.9 27.3 140.133.1 168.1 12.3 138.4 10.9 140.6 27.1 140.332.6 168.6 12.7 138.0 11.1 140.4 27.1 140.331.8 169.4 13.0 137.7 11.1 140.4 27.1 140.331.8 169.4 13.2 137.5 11.1 140.4 26.6 140.828.8 172.4 13.3 137.4 1.2 150.3 Erroneous 26.1 141.327.9 173.3 13.4 137.3 11.3 140.2 25.9 141.528.2 173.0 13.5 137.2 11.7 139.8 25.7 141.729.2 172.0 13.4 137.3 11.2 140.3 25.7 141.730.4 170.8 13.4 137.3 11.2 140.3 24.7 142.731.8 169.4 13.7 137.0 11.2 140.3 26.6 140.832.0 169.2 13.8 136.9 11.3 140.2 26.7 140.731.7 169.5 14.0 136.7 11.3 140.2 26.6 140.831.8 169.4 14.5 136.2 11.4 140.1 26.6 140.829.3 171.9 13.7 137.0 11.4 140.1 25.5 141.9






(ft) (in.)


1/29/2009 182.20 0.392/25/2009 185.70 3.103/26/2009 188.40 0.104/28/2009 189.30 0.005/18/2009 188.50 0.005/27/2009 188.10 0.006/30/2009 188.60 0.107/30/2009 184.80 0.008/26/2009 176.60 0.009/30/2009 174.50 0.00

10/28/2009 175.30 0.2912/1/2009 176.40 0.00

12/28/2009 178.80 2.751/26/2010 191.30 4.152/24/2010 193.60 2.293/29/2010 193.50 1.18

4/4/2010 193.504/27/2010 193.90 1.665/27/2010 192.90 0.036/29/2010 191.60 0.007/28/2010 187.50 0.008/31/2010 179.20 0.009/29/2010 175.60 0.00

10/26/2010 178.20 2.9311/30/2010 178.80 1.1412/30/2010 193.90 9.95

1/27/2011 194.00 0.862/23/2011 193.80 1.023/29/2011 193.90 2.384/27/2011 193.60 0.565/25/2011 193.10 0.516/28/2011 192.00 0.00

169.2 202.3 202.2 184.0152.7 164.3 144.5 160.4

16.5 38.0 57.7 23.6


P-7 P-8A P-8B P-9A

6.0 163.2 34.9 167.4 44.7 157.5 22.7 161.35.8 163.4 34.6 167.7 43.9 158.3 22.4 161.65.0 164.2 33.0 169.3 43.1 159.1 21.9 162.13.7 165.5 31.9 170.4 42.7 159.5 21.4 162.64.5 164.7 31.9 170.4 42.7 159.5 21.0 163.04.6 164.6 31.9 170.4 42.9 159.3 21.0 163.04.3 164.9 31.7 170.6 42.6 159.6 21.0 163.04.5 164.7 32.0 170.3 43.2 159.0 20.9 163.15.8 163.4 33.3 169.0 45.1 157.1 21.4 162.67.7 161.5 35.1 167.2 46.6 155.6 22.2 161.87.8 161.4 35.6 166.7 46.7 155.5 22.5 161.57.7 161.5 36.1 166.2 46.9 155.3 22.8 161.26.8 162.4 36.0 166.3 46.0 156.2 23.0 161.15.5 163.7 35.4 166.9 43.2 159.0 22.9 161.13.2 166.0 31.8 170.5 41.5 160.7 21.6 162.43.4 165.8 31.3 171.0 41.2 161.0 20.2 163.83.6 165.6 30.2 172.1 41.1 161.1 20.3 163.73.4 165.8 29.8 172.5 41.0 161.2 19.5 164.53.4 165.8 29.8 172.5 41.0 161.2 19.4 164.63.1 166.1 29.9 172.4 41.2 161.0 19.4 164.63.3 165.9 30.6 171.7 42.6 159.6 19.8 164.24.6 164.6 32.6 169.7 44.4 157.8 21.0 163.06.3 162.9 34.2 168.1 45.8 156.4 21.5 162.56.8 162.4 35.2 167.1 45.8 156.4 22.3 161.76.4 162.8 35.7 166.6 45.8 156.4 22.8 161.24.1 165.1 33.8 168.5 41.3 160.9 19.6 164.42.9 166.3 30.3 172.0 41.0 161.2 19.2 164.82.8 166.4 29.5 172.9 40.7 161.5 18.7 165.42.7 166.5 28.8 173.5 40.4 161.8 16.3 167.72.8 166.5 29.0 173.3 40.5 161.7 18.2 165.92.5 166.7 29.4 172.9 40.6 161.6 18.8 165.22.5 166.7 29.6 172.7 40.9 161.3 19.2 164.8






(ft) (in.)


7/27/2011 186.75 0.008/25/2011 176.30 0.009/28/2011 176.00 0.06

10/25/2011 176.50 0.8911/22/2011 177.20 1.3112/22/2011 176.70 0.20

1/25/2012 178.60 0.842/28/2012 179.20 0.683/27/2012 180.60 1.736/27/2012 180.70 0.007/26/2012 179.20 0.10

8/8/2012 178.50 0.108/28/2012 177.10 0.008/29/2012 177.10 0.009/25/2012 175.30 0.00

10/30/2012 176.00 0.1911/27/2012 175.80 0.6912/12/2012 176.10 0.70

1/22/2013 177.20 1.402/27/2013 178.20 1.203/28/2013 178.20 0.314/25/2013 177.30 0.715/22/2013 177.60 0.036/25/2013 177.50 0.007/23/2013 175.70 0.008/21/2013 174.50 0.009/25/2013 175.70 0.00

10/29/2013 176.00 0.0011/27/2013 176.50 0.4412/19/2013 176.80 0.53

169.2 202.3 202.2 184.0152.7 164.3 144.5 160.4

16.5 38.0 57.7 23.6


P-7 P-8A P-8B P-9A

2.9 166.3 30.7 171.6 42.1 160.1 19.7 164.34.7 164.5 32.7 169.6 44.8 157.4 20.9 163.16.6 162.6 34.9 167.4 46.0 156.2 22.1 161.96.7 162.5 35.8 166.5 46.1 156.1 22.5 161.56.7 162.6 36.0 166.4 46.2 156.0 22.8 161.26.3 162.9 35.9 166.4 45.9 156.3 22.9 161.16.5 162.7 35.7 166.6 45.5 156.7 22.8 161.26.4 162.8 35.9 166.4 45.6 156.6 22.8 161.26.3 162.9 35.6 166.7 45.0 157.2 23.0 161.15.9 163.3 34.4 167.9 44.6 157.6 22.4 161.66.3 162.9 35.0 167.3 45.1 157.1 22.5 161.56.2 163.0 34.8 167.5 45.2 157.0 22.4 161.66.5 162.7 35.3 167.0 45.6 156.6 22.6 161.46.4 162.8 35.0 167.3 45.5 156.7 22.3 161.77.0 162.2 35.7 166.6 46.3 155.9 22.8 161.27.0 162.2 36.3 166.0 46.4 155.8 23.2 160.87.0 162.2 36.4 165.9 46.5 155.7 23.3 160.76.9 162.3 36.3 166.0 46.3 155.9 23.1 160.96.4 162.8 36.4 165.9 45.8 156.4 23.3 160.76.1 163.1 36.0 166.3 45.4 156.8 23.1 160.96.4 162.8 36.0 166.3 45.5 156.7 23.3 160.76.6 162.6 36.1 166.2 45.8 156.4 23.3 160.86.6 162.6 36.1 166.2 45.7 156.5 23.2 160.86.5 162.7 36.2 166.1 45.7 156.5 23.3 160.76.8 162.4 36.3 166.0 46.3 156.0 23.3 160.77.0 162.2 38.0 164.3 Wet 46.5 155.7 23.3 160.76.8 162.4 36.2 166.1 46.3 155.9 23.4 160.66.5 162.7 36.6 165.7 46.2 156.0 23.5 160.66.1 163.1 36.4 165.9 45.9 156.3 23.3 160.76.2 163.0 36.3 166.0 45.8 156.4 23.2 160.8






(ft) (in.)


1/28/2014 176.80 0.002/25/2014 176.70 0.723/25/2014 178.503/29/2014 178.40 1.444/25/2014 177.40 0.745/28/2014 176.40 0.006/25/2014 176.10 0.007/30/2014 177.30 0.008/26/2014 176.10 0.039/23/2014 175.90 0.00

10/30/2014 176.30 0.0011/21/2014 176.20 0.2512/30/2014 178.90 3.37

1/27/2015 179.60 0.892/27/2015 180.00 0.463/26/2015 179.60 0.454/29/2015 178.20 0.245/27/2015 179.00 1.046/25/2015 179.60 0.007/29/2015 178.10 0.008/26/2015 176.20 0.009/22/2015 178.20 1.64

10/27/2015 176.90 0.1011/24/2015 176.30 0.1712/22/2015 177.60 0.72

1/27/2016 180.10 2.862/25/2016 181.60 0.203/24/2016 184.80 1.483/31/2016 184.50 1.514/28/2016 183.60 0.045/25/2016 182.50 0.136/28/2016 180.70 0.00

169.2 202.3 202.2 184.0152.7 164.3 144.5 160.4

16.5 38.0 57.7 23.6


P-7 P-8A P-8B P-9A

6.2 163.0 36.5 165.8 45.9 156.3 23.5 160.56.3 163.0 36.5 165.8 45.9 156.3 23.5 160.56.0 163.3 36.2 166.1 45.4 156.9 23.4 160.65.9 163.3 36.4 165.9 45.5 156.7 23.5 160.56.1 163.1 36.1 166.2 45.5 156.7 23.3 160.76.6 162.6 36.3 166.0 46.0 156.2 23.3 160.76.4 162.8 36.4 165.9 44.9 157.3 23.3 160.76.2 163.0 36.3 166.0 45.6 156.7 23.2 160.96.1 163.1 36.2 166.1 45.6 156.6 23.6 160.4 Dry6.0 163.2 36.4 166.0 45.7 156.5 23.3 160.85.9 163.3 36.3 166.0 45.8 156.4 23.3 160.75.8 163.4 36.3 166.0 45.5 156.7 23.2 160.85.3 163.9 36.0 166.3 44.9 157.3 23.1 160.95.2 164.0 35.8 166.5 44.6 157.6 23.2 160.95.2 164.0 35.2 167.1 44.3 157.9 22.8 161.25.3 163.9 35.3 167.0 44.4 157.8 22.8 161.25.6 163.6 35.3 167.0 44.8 157.4 22.6 161.45.8 163.4 35.7 166.6 45.0 157.2 22.9 161.15.2 164.0 35.2 167.1 44.5 157.7 23.0 161.05.4 163.8 35.3 167.0 44.8 157.4 22.6 161.45.6 163.6 35.6 166.7 45.2 157.0 22.7 161.35.6 163.6 35.8 166.5 44.9 157.3 22.9 161.15.4 163.8 35.8 166.5 45.0 157.2 22.5 161.55.6 163.6 35.8 166.5 45.3 156.9 23.2 160.85.5 163.7 35.8 166.5 44.9 157.3 22.9 161.1 VW installed5.3 163.9 36.0 166.3 44.7 157.5 23.5 160.55.0 164.2 34.9 167.4 43.8 158.4 23.5 160.54.8 164.4 34.5 167.8 43.3 158.9 23.4 160.64.7 164.5 34.4 167.9 43.1 159.1 23.3 160.74.8 164.4 33.8 168.5 43.2 159.0 23.2 160.84.7 164.5 34.1 168.2 43.6 158.6 22.9 161.14.8 164.4 34.3 168.0 43.9 158.3 23.1 160.9






(ft) (in.)


7/27/2016 178.40 0.008/24/2016 176.40 0.009/27/2016 175.80 0.00

10/26/2016 178.60 0.6411/22/2016 178.30 1.1112/28/2016 184.80 4.01

1/25/2017 193.30 6.332/28/2017 193.90 3.273/29/2017 193.70 0.084/27/2017 192.90 0.045/23/2017 187.90 0.336/21/2017 182.50 0.007/26/2017 163.60 0.008/30/2017 163.60 0.009/28/2017 163.60 0.00

10/26/2017 171.80 0.0011/29/2017 177.20 0.0812/27/2017 176.70 0.00

1/24/2018 178.10 1.672/21/2018 177.80 0.273/28/2018 183.50 1.234/27/2018 184.30 0.055/30/2018 183.10 0.136/28/2018 181.70 0.007/26/2018 180.00 0.008/28/2018 177.30 0.009/27/2018 178.10 0.00

10/24/2018 178.00 0.6611/29/2018 177.50 1.6012/20/2018 181.40 2.39

169.2 202.3 202.2 184.0152.7 164.3 144.5 160.4

16.5 38.0 57.7 23.6


P-7 P-8A P-8B P-9A

5.1 164.1 34.6 167.7 44.6 157.6 23.2 160.85.7 163.5 35.3 167.0 45.1 157.1 23.4 160.66.1 163.1 35.8 166.5 45.5 156.7 23.5 160.55.3 163.9 35.8 166.5 44.8 157.4 23.6 160.45.6 163.7 35.7 166.6 44.8 157.4 VW not logging5.2 164.0 35.5 166.8 44.0 158.2 23.4 160.63.9 165.3 33.9 168.4 41.1 161.1 22.3 161.73.2 166.0 30.7 171.6 40.5 161.7 21.2 162.83.0 166.2 30.0 172.3 40.3 161.9 20.5 163.52.7 166.5 29.7 172.6 40.0 162.2 20.4 163.63.0 166.2 30.5 171.8 41.2 161.0 23.4 160.63.5 165.7 31.9 170.4 42.6 159.6 21.3 162.75.8 163.4 34.5 167.8 46.7 155.5 22.8 161.38.7 160.5 36.4 165.9 48.6 153.6 23.5 160.512.6 156.6 37.5 164.8 49.7 152.5 23.6 160.414.5 154.7 37.7 164.6 48.8 153.4 23.6 160.49.7 159.5 37.2 165.1 46.3 155.9 23.6 160.47.6 161.6 36.7 165.6 46.1 156.1 23.6 160.47.7 161.5 36.3 166.0 45.4 156.8 23.6 160.46.8 162.4 36.1 166.2 45.3 156.9 23.6 160.45.9 163.3 35.6 166.7 44.0 158.2 23.3 160.75.2 164.0 34.8 167.5 43.5 158.7 23.6 160.45.3 163.9 34.2 168.1 43.6 158.6 0.25 183.8 Erroneous5.7 163.5 34.2 168.1 44.0 158.2 23.3 160.76.0 163.2 34.5 167.8 44.4 157.8 23.9 160.1 Erroneous6.7 162.5 35.2 167.2 45.3 156.9 23.4 160.67.0 162.2 35.5 166.8 45.5 156.7 23.6 160.46.2 163.0 35.6 166.7 45.3 156.9 23.6 160.46.9 162.3 35.5 166.8 45.5 156.7 23.6 160.46.6 162.6 35.3 167.0 44.4 157.8 23.6 160.4






(ft) (in.)


1/29/2009 182.20 0.392/25/2009 185.70 3.103/26/2009 188.40 0.104/28/2009 189.30 0.005/18/2009 188.50 0.005/27/2009 188.10 0.006/30/2009 188.60 0.107/30/2009 184.80 0.008/26/2009 176.60 0.009/30/2009 174.50 0.00

10/28/2009 175.30 0.2912/1/2009 176.40 0.00

12/28/2009 178.80 2.751/26/2010 191.30 4.152/24/2010 193.60 2.293/29/2010 193.50 1.18

4/4/2010 193.504/27/2010 193.90 1.665/27/2010 192.90 0.036/29/2010 191.60 0.007/28/2010 187.50 0.008/31/2010 179.20 0.009/29/2010 175.60 0.00

10/26/2010 178.20 2.9311/30/2010 178.80 1.1412/30/2010 193.90 9.95

1/27/2011 194.00 0.862/23/2011 193.80 1.023/29/2011 193.90 2.384/27/2011 193.60 0.565/25/2011 193.10 0.516/28/2011 192.00 0.00

184.2 183.4 183.7 165.6151.7 148.0 136.1 155.4

32.5 35.4 47.6 10.2


P-9B P-10A P-10B P-11

28.2 156.0 21.5 161.9 43.9 139.8 9.1 156.528.0 156.2 21.4 162.0 43.0 140.7 8.9 156.727.5 156.7 20.9 162.5 43.6 140.1 8.8 156.827.1 157.1 20.2 163.2 43.7 140.0 8.5 157.126.8 157.4 19.6 163.8 43.4 140.3 8.4 157.226.8 157.4 19.4 164.0 43.6 140.1 8.4 157.226.7 157.5 19.2 164.2 43.7 140.0 8.4 157.226.7 157.5 19.2 164.2 43.9 139.8 8.3 157.327.0 157.2 19.5 163.9 44.1 139.6 8.3 157.327.7 156.5 20.4 163.0 45.1 138.6 8.7 156.928.0 156.2 20.8 162.6 44.4 139.3 8.9 156.728.4 155.8 21.0 162.4 45.0 138.7 9.0 156.628.5 155.8 21.8 161.6 44.5 139.2 9.2 156.528.3 155.9 21.5 161.9 43.0 140.7 8.1 157.527.2 157.0 20.5 162.9 42.4 141.3 8.3 157.326.1 158.1 19.1 164.3 42.4 141.3 8.1 157.526.0 158.2 18.7 164.7 42.6 141.1 8.2 157.425.8 158.4 18.4 165.0 42.5 141.2 8.0 157.625.7 158.5 18.2 165.2 42.4 141.3 7.8 157.825.8 158.4 18.1 165.3 42.2 141.5 7.9 157.726.1 158.1 18.3 165.1 42.9 140.8 8.0 157.626.8 157.4 18.9 164.5 42.9 140.8 7.9 157.727.2 157.0 19.3 164.1 44.0 139.7 8.0 157.627.8 156.4 20.3 163.1 44.3 139.4 8.6 157.028.4 155.8 21.3 162.1 44.6 139.1 8.9 156.727.0 157.2 19.5 163.9 42.1 141.6 7.5 158.126.0 158.2 18.8 164.6 42.7 141.1 7.8 157.825.6 158.7 18.2 165.2 42.4 141.3 7.9 157.824.6 159.6 16.8 166.6 41.9 141.8 7.6 158.025.0 159.2 17.0 166.4 42.4 141.3 7.8 157.825.5 158.7 17.6 165.8 42.3 141.4 7.9 157.725.8 158.4 18.3 165.1 42.4 141.3 8.0 157.6






(ft) (in.)


7/27/2011 186.75 0.008/25/2011 176.30 0.009/28/2011 176.00 0.06

10/25/2011 176.50 0.8911/22/2011 177.20 1.3112/22/2011 176.70 0.20

1/25/2012 178.60 0.842/28/2012 179.20 0.683/27/2012 180.60 1.736/27/2012 180.70 0.007/26/2012 179.20 0.10

8/8/2012 178.50 0.108/28/2012 177.10 0.008/29/2012 177.10 0.009/25/2012 175.30 0.00

10/30/2012 176.00 0.1911/27/2012 175.80 0.6912/12/2012 176.10 0.70

1/22/2013 177.20 1.402/27/2013 178.20 1.203/28/2013 178.20 0.314/25/2013 177.30 0.715/22/2013 177.60 0.036/25/2013 177.50 0.007/23/2013 175.70 0.008/21/2013 174.50 0.009/25/2013 175.70 0.00

10/29/2013 176.00 0.0011/27/2013 176.50 0.4412/19/2013 176.80 0.53

184.2 183.4 183.7 165.6151.7 148.0 136.1 155.4

32.5 35.4 47.6 10.2


P-9B P-10A P-10B P-11

26.1 158.1 18.4 165.1 42.6 141.1 8.2 157.426.9 157.3 18.5 164.9 43.4 140.3 8.5 157.127.7 156.5 20.0 163.5 44.5 139.2 8.7 156.928.1 156.1 20.6 162.8 44.8 138.9 8.9 156.728.4 155.8 21.2 162.2 44.7 139.0 9.0 156.628.5 155.7 21.6 161.8 45.2 138.5 8.9 156.728.3 155.9 21.4 162.0 44.2 139.5 9.2 156.428.6 155.6 21.7 161.7 44.2 139.5 9.4 156.228.4 155.8 21.8 161.7 43.8 139.9 9.2 156.427.9 156.3 20.2 163.2 44.1 139.6 9.6 156.028.2 156.0 21.5 161.9 44.4 139.3 9.2 156.428.0 156.2 21.1 162.3 44.9 138.8 9.0 156.628.2 156.0 21.3 162.1 45.3 138.4 9.1 156.527.8 156.4 20.9 162.5 45.7 138.0 8.9 156.728.3 155.9 21.4 162.0 46.2 137.5 9.1 156.528.6 155.6 21.8 161.6 46.3 137.4 9.2 156.428.8 155.4 22.1 161.3 46.1 137.6 9.3 156.328.6 155.6 22.0 161.5 45.6 138.1 9.3 156.328.8 155.4 22.3 161.1 44.6 139.1 9.2 156.428.6 155.6 22.2 161.2 44.4 139.3 9.4 156.228.7 155.5 22.3 161.1 44.1 139.6 9.5 156.128.7 155.5 22.3 161.1 45.0 138.7 9.5 156.128.5 155.7 22.3 161.1 44.9 138.8 9.5 156.128.7 155.5 22.4 161.1 45.0 138.7 9.6 156.128.7 155.5 22.3 161.1 45.7 138.0 9.5 156.228.6 155.6 22.3 161.1 46.1 137.6 9.4 156.228.7 155.5 22.0 161.4 46.4 137.3 9.4 156.228.8 155.4 22.5 160.9 42.3 141.5 Erroneous 9.4 156.228.6 155.6 22.5 160.9 46.2 137.5 9.3 156.328.6 155.6 22.5 160.9 45.6 138.1 9.5 156.1






(ft) (in.)


1/28/2014 176.80 0.002/25/2014 176.70 0.723/25/2014 178.503/29/2014 178.40 1.444/25/2014 177.40 0.745/28/2014 176.40 0.006/25/2014 176.10 0.007/30/2014 177.30 0.008/26/2014 176.10 0.039/23/2014 175.90 0.00

10/30/2014 176.30 0.0011/21/2014 176.20 0.2512/30/2014 178.90 3.37

1/27/2015 179.60 0.892/27/2015 180.00 0.463/26/2015 179.60 0.454/29/2015 178.20 0.245/27/2015 179.00 1.046/25/2015 179.60 0.007/29/2015 178.10 0.008/26/2015 176.20 0.009/22/2015 178.20 1.64

10/27/2015 176.90 0.1011/24/2015 176.30 0.1712/22/2015 177.60 0.72

1/27/2016 180.10 2.862/25/2016 181.60 0.203/24/2016 184.80 1.483/31/2016 184.50 1.514/28/2016 183.60 0.045/25/2016 182.50 0.136/28/2016 180.70 0.00

184.2 183.4 183.7 165.6151.7 148.0 136.1 155.4

32.5 35.4 47.6 10.2


P-9B P-10A P-10B P-11

28.9 155.3 22.9 160.5 45.4 138.3 9.6 156.028.9 155.3 22.9 160.5 45.2 138.5 9.6 156.028.8 155.5 22.9 160.6 44.6 139.1 9.6 156.028.9 155.3 22.9 160.5 44.7 139.0 9.3 156.328.7 155.5 22.7 160.7 44.8 138.9 9.5 156.128.8 155.4 22.7 160.7 43.3 140.4 9.6 156.028.8 155.4 22.7 160.7 46.3 137.4 8.9 156.728.6 155.7 22.6 160.9 46.9 136.8 9.3 156.332.5 151.7 Dry; Erroneous 22.5 160.9 42.5 141.2 Erroneous 9.5 156.128.7 155.5 22.7 160.7 46.6 137.2 9.4 156.328.7 155.5 22.7 160.7 46.6 137.1 9.3 156.328.6 155.6 22.7 160.7 45.0 138.7 9.1 156.528.5 155.7 22.8 160.6 45.1 138.6 9.4 156.228.6 155.6 22.8 160.6 44.8 138.9 9.3 156.328.2 156.0 22.4 161.0 44.3 139.4 9.1 156.528.2 156.0 22.3 161.1 42.5 141.2 Erroneous 9.1 156.528.1 156.1 22.1 161.3 42.4 141.3 Erroneous 9.0 156.628.5 155.7 22.2 161.2 44.0 139.7 9.3 156.328.3 155.9 22.1 161.3 46.9 136.8 Dry 9.0 156.628.0 156.2 22.0 161.4 45.0 138.7 8.9 156.728.0 156.2 21.2 162.2 40.6 143.1 Erroneous 8.9 156.728.2 156.0 22.1 161.3 45.4 138.3 9.0 156.628.3 155.9 22.2 161.2 45.8 137.9 9.2 156.428.5 155.7 22.3 161.1 42.7 141.0 Erroneous 9.3 156.328.7 155.5 VW installed 22.7 160.7 VW installed 45.7 138.0 VW installed 9.3 156.3 VW installed29.4 154.8 24.7 158.7 45.7 138.0 10.1 155.529.3 154.9 24.6 158.9 46.5 137.2 10.1 155.529.1 155.1 24.3 159.1 46.3 137.4 10.1 155.529.1 155.1 24.3 159.1 46.5 137.2 10.1 155.528.9 155.3 24.0 159.4 46.9 136.8 10.2 155.428.8 155.4 23.7 159.7 46.8 136.9 9.8 155.828.9 155.3 23.6 159.8 47.1 136.6 9.9 155.7






(ft) (in.)


7/27/2016 178.40 0.008/24/2016 176.40 0.009/27/2016 175.80 0.00

10/26/2016 178.60 0.6411/22/2016 178.30 1.1112/28/2016 184.80 4.01

1/25/2017 193.30 6.332/28/2017 193.90 3.273/29/2017 193.70 0.084/27/2017 192.90 0.045/23/2017 187.90 0.336/21/2017 182.50 0.007/26/2017 163.60 0.008/30/2017 163.60 0.009/28/2017 163.60 0.00

10/26/2017 171.80 0.0011/29/2017 177.20 0.0812/27/2017 176.70 0.00

1/24/2018 178.10 1.672/21/2018 177.80 0.273/28/2018 183.50 1.234/27/2018 184.30 0.055/30/2018 183.10 0.136/28/2018 181.70 0.007/26/2018 180.00 0.008/28/2018 177.30 0.009/27/2018 178.10 0.00

10/24/2018 178.00 0.6611/29/2018 177.50 1.6012/20/2018 181.40 2.39

184.2 183.4 183.7 165.6151.7 148.0 136.1 155.4

32.5 35.4 47.6 10.2


P-9B P-10A P-10B P-11

29.0 155.2 23.6 159.8 47.5 136.2 9.9 155.729.1 155.1 23.6 159.8 47.6 136.1 9.8 155.829.4 154.8 23.9 159.5 47.6 136.1 10.0 155.629.5 154.7 24.1 159.3 47.6 136.1 10.0 155.6

VW not logging VW not logging VW not logging VW not logging29.3 154.9 24.2 159.2 45.5 138.3 10.1 155.528.2 156.0 23.0 160.4 42.9 140.8 9.5 156.127.4 156.8 21.3 162.1 43.1 140.6 9.0 156.627.0 157.2 20.5 162.9 43.7 140.0 9.0 156.627.0 157.2 20.6 162.8 43.9 139.8 9.2 156.427.3 156.9 23.0 160.4 Erroneous 44.0 139.7 9.7 155.927.7 156.5 21.1 162.3 44.8 138.9 9.3 156.328.6 155.6 22.0 161.4 46.6 137.1 9.5 156.129.4 154.8 23.1 160.3 47.6 136.1 9.8 155.829.8 154.4 23.8 159.6 47.6 136.1 9.9 155.729.9 154.3 24.3 159.1 47.6 136.1 37.3 128.3 Erroneous30.0 154.2 24.7 158.7 47.6 136.1 10.2 155.429.8 154.4 24.7 158.7 47.6 136.1 10.2 155.429.8 154.4 24.7 158.7 47.6 136.1 10.2 155.429.8 154.4 24.7 158.7 47.6 136.1 10.2 155.429.7 154.5 24.6 158.8 47.6 136.1 10.2 155.429.4 154.8 24.4 159.0 47.6 136.1 10.2 155.429.2 155.0 24.4 159.0 47.6 136.1 10.2 155.429.0 155.2 23.6 159.8 47.6 136.1 28.2 137.4 Erroneous29.1 155.1 23.5 159.9 47.6 136.1 10.0 155.629.2 155.0 23.5 159.9 47.6 136.1 9.9 155.729.4 154.8 23.7 159.7 47.6 136.1 10.0 155.629.4 154.8 23.9 159.5 47.6 136.1 10.1 155.529.6 154.6 24.2 159.2 47.6 136.1 10.2 155.429.5 154.7 24.1 159.3 46.8 136.9 10.1 155.5






(ft) (in.)


1/29/2009 182.20 0.392/25/2009 185.70 3.103/26/2009 188.40 0.104/28/2009 189.30 0.005/18/2009 188.50 0.005/27/2009 188.10 0.006/30/2009 188.60 0.107/30/2009 184.80 0.008/26/2009 176.60 0.009/30/2009 174.50 0.00

10/28/2009 175.30 0.2912/1/2009 176.40 0.00

12/28/2009 178.80 2.751/26/2010 191.30 4.152/24/2010 193.60 2.293/29/2010 193.50 1.18

4/4/2010 193.504/27/2010 193.90 1.665/27/2010 192.90 0.036/29/2010 191.60 0.007/28/2010 187.50 0.008/31/2010 179.20 0.009/29/2010 175.60 0.00

10/26/2010 178.20 2.9311/30/2010 178.80 1.1412/30/2010 193.90 9.95

1/27/2011 194.00 0.862/23/2011 193.80 1.023/29/2011 193.90 2.384/27/2011 193.60 0.565/25/2011 193.10 0.516/28/2011 192.00 0.00

160.5 160.1151.5 150.6

9.0 9.5Left Right

Reading Elev. Comment Reading Elev. Comment Subdrain Subdrain(ft) (ft) (ft) (ft) (Gal/Min) (Gal/Min)

P-13

Drain ID

P-12

8.6 151.9 8.5 151.6 0.68 0.007.7 152.8 7.5 152.6 1.06 0.008.5 152.0 8.5 151.6 1.59 0.008.6 151.9 8.9 151.2 2.26 0.007.8 152.7 9.0 151.1 2.18 0.008.7 151.8 Dry 9.1 151.0 1.98 0.007.8 152.7 8.6 151.5 2.98 0.008.1 152.4 8.4 151.7 2.26 0.008.0 152.5 8.1 152.0 0.63 0.007.9 152.6 8.4 151.7 0.01 0.008.0 152.5 8.5 151.6 0.00 0.008.0 152.5 8.7 151.4 0.00 0.008.2 152.3 8.6 151.5 0.21 0.005.6 154.9 4.9 155.2 1.06 0.007.1 153.4 6.7 153.4 2.88 0.007.3 153.2 6.8 153.3 1.82 0.007.5 153.0 7.0 153.1 2.54 0.007.3 153.2 6.8 153.3 0.75 0.007.4 153.1 7.5 152.6 3.17 0.007.7 152.8 8.6 151.5 2.38 0.007.5 153.0 7.1 153.0 1.59 0.007.4 153.1 7.7 152.4 0.98 0.007.3 153.2 7.3 152.8 0.13 0.007.5 153.0 Dry; Erroneous 7.6 152.5 0.20 0.008.0 152.5 8.6 151.5 0.32 0.004.6 155.9 3.7 156.4 2.51 0.006.4 154.2 5.9 154.2 2.25 0.006.5 154.0 6.1 154.0 1.46 0.004.8 155.7 3.8 156.3 0.87 0.006.0 154.6 5.2 154.9 0.79 0.006.8 153.7 6.2 153.9 0.79 0.007.8 152.7 7.3 152.8 1.59 0.00






(ft) (in.)


7/27/2011 186.75 0.008/25/2011 176.30 0.009/28/2011 176.00 0.06

10/25/2011 176.50 0.8911/22/2011 177.20 1.3112/22/2011 176.70 0.20

1/25/2012 178.60 0.842/28/2012 179.20 0.683/27/2012 180.60 1.736/27/2012 180.70 0.007/26/2012 179.20 0.10

8/8/2012 178.50 0.108/28/2012 177.10 0.008/29/2012 177.10 0.009/25/2012 175.30 0.00

10/30/2012 176.00 0.1911/27/2012 175.80 0.6912/12/2012 176.10 0.70

1/22/2013 177.20 1.402/27/2013 178.20 1.203/28/2013 178.20 0.314/25/2013 177.30 0.715/22/2013 177.60 0.036/25/2013 177.50 0.007/23/2013 175.70 0.008/21/2013 174.50 0.009/25/2013 175.70 0.00

10/29/2013 176.00 0.0011/27/2013 176.50 0.4412/19/2013 176.80 0.53

160.5 160.1151.5 150.6

9.0 9.5Left Right


P-13

Drain ID

P-12

7.7 152.9 7.0 153.1 0.98 0.007.7 152.8 7.8 152.3 0.69 0.007.8 152.7 7.9 152.3 0.13 0.007.9 152.6 8.3 151.8 0.26 0.008.4 152.1 8.4 151.8 0.24 0.008.7 151.8 8.5 151.6 0.30 0.007.8 152.7 8.6 151.5 0.32 0.008.0 152.5 8.6 151.5 0.40 0.007.9 152.6 8.6 151.5 0.43 0.008.9 151.6 9.4 150.7 0.13 0.008.8 151.7 9.5 150.6 0.12 0.008.9 151.6 8.6 151.5 0.32 0.008.9 151.6 9.4 150.7 0.24 0.009.2 151.3 Erroneous 8.6 151.5 0.18 0.008.9 151.6 9.4 150.7 0.07 0.008.9 151.6 9.3 150.8 0.12 0.009.0 151.5 9.2 150.9 0.13 0.009.0 151.6 9.0 151.1 0.13 0.009.0 151.5 9.3 150.8 0.24 0.008.9 151.6 9.2 150.9 0.14 0.009.0 151.5 9.4 150.7 0.32 0.009.0 151.5 9.4 150.7 0.34 0.009.0 151.5 9.4 150.7 0.16 0.008.9 151.6 9.2 150.9 0.23 0.008.9 151.6 Dry 9.3 150.8 Dry 0.12 0.009.0 151.5 Dry 9.5 150.6 Dry 0.10 0.009.0 151.5 Dry 9.4 150.7 Dry 0.16 0.009.0 151.5 Dry 9.4 150.7 Dry 0.22 0.008.9 151.6 Wet 9.2 150.9 Wet 0.25 0.009.0 151.5 Dry 9.4 150.7 Dry 0.40 0.00






(ft) (in.)


1/28/2014 176.80 0.002/25/2014 176.70 0.723/25/2014 178.503/29/2014 178.40 1.444/25/2014 177.40 0.745/28/2014 176.40 0.006/25/2014 176.10 0.007/30/2014 177.30 0.008/26/2014 176.10 0.039/23/2014 175.90 0.00

10/30/2014 176.30 0.0011/21/2014 176.20 0.2512/30/2014 178.90 3.37

1/27/2015 179.60 0.892/27/2015 180.00 0.463/26/2015 179.60 0.454/29/2015 178.20 0.245/27/2015 179.00 1.046/25/2015 179.60 0.007/29/2015 178.10 0.008/26/2015 176.20 0.009/22/2015 178.20 1.64

10/27/2015 176.90 0.1011/24/2015 176.30 0.1712/22/2015 177.60 0.72

1/27/2016 180.10 2.862/25/2016 181.60 0.203/24/2016 184.80 1.483/31/2016 184.50 1.514/28/2016 183.60 0.045/25/2016 182.50 0.136/28/2016 180.70 0.00

160.5 160.1151.5 150.6

9.0 9.5Left Right


P-13

Drain ID

P-12

9.0 151.5 Dry 9.4 150.7 Dry 0.37 0.009.0 151.5 Dry 9.4 150.7 Dry 0.22 0.009.0 151.5 Dry 9.4 150.7 Dry 0.25 0.009.0 151.5 Dry 9.4 150.7 Dry 0.47 0.009.0 151.5 Dry 9.5 150.6 Dry 0.32 0.009.0 151.5 Dry 9.3 150.8 Dry 0.04 0.009.0 151.5 Dry 9.5 150.6 Dry 0.21 0.009.0 151.5 Dry 9.4 150.7 Dry 0.28 0.009.0 151.5 Dry 9.4 150.7 Dry 0.29 0.008.9 151.7 Dry 9.2 150.9 Dry 0.26 0.008.0 152.5 Wet 8.5 151.6 Dry 0.29 0.008.9 151.6 Dry 9.2 150.9 Dry 0.32 0.008.8 151.7 Dry 9.2 150.9 Dry 0.42 0.008.9 151.6 Dry 9.1 151.0 Wet 0.40 0.008.9 151.6 Dry 9.1 151.0 Wet 0.52 0.009.0 151.5 Dry 8.9 151.2 0.61 0.008.9 151.6 Dry 9.2 150.9 Dry 0.55 0.008.9 151.6 Dry 9.3 150.8 Dry 0.48 0.008.9 151.6 Dry 9.3 150.8 Dry 0.44 0.008.9 151.6 Wet 9.3 150.8 Wet 0.55 0.008.9 151.6 Dry 9.3 150.8 Dry 0.13 0.008.9 151.6 Dry 9.3 150.8 Dry 0.61 0.008.9 151.6 Dry 9.3 150.8 Dry 0.42 0.009.0 151.5 Dry 9.3 150.8 Dry 0.40 0.009.0 151.5 Dry; VW installed 8.4 151.7 VW installed 0.41 0.008.9 151.6 9.4 150.7 0.37 0.009.0 151.5 Dry 9.5 150.6 Dry 0.57 0.008.9 151.6 9.5 150.6 0.60 0.008.9 151.6 9.5 150.6 2.03 0.009.0 151.5 9.5 150.6 1.76 0.009.0 151.5 9.5 150.6 1.61 0.009.0 151.5 9.5 150.6 1.11 0.00






(ft) (in.)


7/27/2016 178.40 0.008/24/2016 176.40 0.009/27/2016 175.80 0.00

10/26/2016 178.60 0.6411/22/2016 178.30 1.1112/28/2016 184.80 4.01

1/25/2017 193.30 6.332/28/2017 193.90 3.273/29/2017 193.70 0.084/27/2017 192.90 0.045/23/2017 187.90 0.336/21/2017 182.50 0.007/26/2017 163.60 0.008/30/2017 163.60 0.009/28/2017 163.60 0.00

10/26/2017 171.80 0.0011/29/2017 177.20 0.0812/27/2017 176.70 0.00

1/24/2018 178.10 1.672/21/2018 177.80 0.273/28/2018 183.50 1.234/27/2018 184.30 0.055/30/2018 183.10 0.136/28/2018 181.70 0.007/26/2018 180.00 0.008/28/2018 177.30 0.009/27/2018 178.10 0.00

10/24/2018 178.00 0.6611/29/2018 177.50 1.6012/20/2018 181.40 2.39

160.5 160.1151.5 150.6

9.0 9.5Left Right


P-13

Drain ID

P-12

9.0 151.5 9.5 150.6 1.02 0.009.0 151.5 9.5 150.6 0.61 0.009.0 151.5 9.5 150.6 0.40 0.009.0 151.5 9.5 150.6 0.88 0.00

VW not logging VW not logging 0.92 0.009.0 151.5 9.5 150.6 1.36 0.004.7 155.8 7.7 152.4 2.01 0.003.8 156.7 6.5 153.6 1.72 0.004.9 155.6 7.7 152.4 1.66 0.005.5 155.0 8.2 151.9 2.77 0.009.0 151.5 9.0 151.1 3.29 0.008.9 151.6 8.6 151.5 2.06 0.008.8 151.7 8.5 151.6 0.26 0.008.4 152.1 9.2 150.9 0.00 0.009.0 151.5 9.5 150.6 0.00 0.009.0 151.5 9.5 150.6 0.00 0.009.0 151.5 9.5 150.6 0.00 0.009.0 151.5 9.5 150.6 0.00 0.009.0 151.5 9.5 150.6 0.02 0.009.0 151.5 9.5 150.6 0.00 0.009.0 151.5 9.5 150.6 0.14 0.009.0 151.5 9.5 150.6 0.29 0.009.0 151.5 9.5 150.6 0.22 0.009.0 151.5 9.5 150.6 0.15 0.009.0 151.5 9.5 150.6 0.03 0.009.0 151.5 9.5 150.6 0.00 0.009.0 151.5 9.5 150.6 0.00 0.009.0 151.5 9.5 150.6 0.00 0.009.0 151.5 9.5 150.6 0.00 0.009.0 151.5 9.5 150.6 0.08 0.00



HORIZONTAL OFFSET OF SURVEY MONUMENTS RELATIVE TO ORIGINAL BASELINE1975 THROUGH 2018


Year Date (feet) (inches) (feet) (inches) (feet) (inches) (feet) (inches) (feet) (inches) (feet) (inches)1975 9/15/1975 0.050 0.600 0.060 0.720 0.050 0.600 0.040 0.480 0.000 0.000 Initial Reading for S-1 to S-51976 Data were not found1977 Data were not found1978 Data were not found1979 Data were not found1980 Data were not found1981 12/15/1981 0.070 0.840 0.080 0.960 0.080 0.960 0.040 0.480 0.100 1.2001982 6/15/1982 0.030 0.360 0.070 0.840 0.100 1.200 0.080 0.960 0.050 0.6001983 Data were not found1984 Data were not found1985 10/20/1985 0.070 0.840 0.090 1.080 0.120 1.440 0.130 1.560 0.060 0.7201986 Data were not found1987 10/20/1987 0.080 0.960 0.120 1.440 0.110 1.320 0.110 1.320 0.150 1.800 0.060 0.720 Initial Reading for S-61988 Data were not found1989 Data were not found1990 Data were not found1991 Data were not found1992 Data were not found1993 Data were not found1994 Data were not found1995 5/8/1995 0.060 0.720 0.080 0.960 0.130 1.560 0.120 1.440 0.120 1.440 0.040 0.4801996 5/1/1996 0.080 0.960 0.100 1.200 0.120 1.440 0.120 1.440 0.150 1.800 0.050 0.6001997 5/28/1997 0.070 0.840 0.080 0.960 0.100 1.200 0.100 1.200 0.130 1.560 0.050 0.6001998 5/11/1998 0.070 0.840 0.080 0.960 0.100 1.200 0.100 1.200 0.120 1.440 0.010 0.1201999 4/26/1999 0.070 0.840 0.090 1.080 0.100 1.200 0.095 1.140 0.115 1.380 0.015 0.1802000 6/29/2000 0.075 0.900 0.090 1.080 0.105 1.260 0.095 1.140 0.120 1.440 0.015 0.1802001 5/2/2001 0.075 0.900 0.090 1.080 0.100 1.200 0.095 1.140 0.110 1.320 0.020 0.2402002 5/21/2002 0.070 0.840 0.090 1.080 0.120 1.440 0.100 1.200 0.105 1.260 0.020 0.2402003 5/21/2003 0.075 0.900 0.095 1.140 0.115 1.380 0.100 1.200 0.110 1.320 0.015 0.1802004 5/18/2004 0.070 0.840 0.100 1.200 0.120 1.440 0.100 1.200 0.115 1.380 0.020 0.2402005 5/31/2005 0.070 0.840 0.100 1.200 0.105 1.260 0.100 1.200 0.115 1.380 0.020 0.2402006 5/31/2006 0.070 0.840 0.095 1.140 0.110 1.320 0.100 1.200 0.115 1.380 0.010 0.1202007 5/15/2007 0.080 0.960 0.085 1.020 0.105 1.260 0.090 1.080 0.105 1.260 0.020 0.2402008 5/27/2008 0.080 0.960 0.085 1.020 0.105 1.260 0.100 1.200 0.120 1.440 0.020 0.2402009 6/9/2009 0.065 0.780 0.085 1.020 0.095 1.140 0.100 1.200 0.120 1.440 0.020 0.2402010 5/24/2010 0.060 0.720 0.080 0.960 0.110 1.320 0.090 1.080 0.105 1.260 0.020 0.240

S-18+00.234

S-26+00.212

S-3 S-50+00.079

Monument ID →

CommentApprox. Station → 4+00.125

S-42+00.191

S-60+61.430

Note:(1) Positive values represent downstream offset (North). IRVINE RANCH WATER DISTRICT Page 1 of 2


HORIZONTAL OFFSET OF SURVEY MONUMENTS RELATIVE TO ORIGINAL BASELINE1975 THROUGH 2018


Year Date (feet) (inches) (feet) (inches) (feet) (inches) (feet) (inches) (feet) (inches) (feet) (inches)

S-18+00.234

S-26+00.212

S-3 S-50+00.079

Monument ID →


S-42+00.191

S-60+61.430

2011 5/18/2011 0.065 0.780 0.080 0.960 0.110 1.320 0.110 1.320 0.120 1.440 0.020 0.2402012 5/18/2012 0.065 0.780 0.085 1.020 0.110 1.320 0.105 1.260 0.120 1.440 0.020 0.2402013 6/6/2013 0.065 0.780 0.105 1.260 0.100 1.200 0.100 1.200 0.115 1.380 0.015 0.1802014 4/25/2014 0.095 1.140 0.100 1.200 0.130 1.560 0.100 1.200 0.120 1.440 0.015 0.1802015 6/4/2015 0.080 0.960 0.080 0.960 0.115 1.380 0.105 1.260 0.115 1.380 0.020 0.2402016 7/25/2016 0.080 0.960 0.085 1.020 0.115 1.380 0.110 1.320 0.125 1.500 0.015 0.1802017 No survey was done in 20172018 5/31/2018 0.080 0.960 0.090 1.080 0.115 1.380 0.105 1.260 0.125 1.500 0.025 0.300

Note:(1) Positive values represent downstream offset (North). IRVINE RANCH WATER DISTRICT Page 2 of 2


NET HORIZONTAL DISPLACEMENT OF SURVEY MONUMENTS1975 THROUGH 2018


Year Date (feet) (inches) (feet) (inches) (feet) (inches) (feet) (inches) (feet) (inches) (feet) (inches)1975 9/15/1975 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 Initial Reading for S-1 to S-51976 Data were not found1977 Data were not found1978 Data were not found1979 Data were not found1980 Data were not found1981 12/15/1981 0.020 0.240 0.020 0.240 0.030 0.360 0.000 0.000 0.100 1.2001982 6/15/1982 -0.020 -0.240 0.010 0.120 0.050 0.600 0.040 0.480 0.050 0.6001983 Data were not found1984 Data were not found1985 10/20/1985 0.020 0.240 0.030 0.360 0.070 0.840 0.090 1.080 0.060 0.7201986 0.000 Data were not found1987 10/20/1987 0.030 0.360 0.060 0.720 0.060 0.720 0.070 0.840 0.000 0.000 0.060 0.720 Initial Reading for S-61988 Data were not found1989 Data were not found1990 Data were not found1991 Data were not found1992 Data were not found1993 Data were not found1994 Data were not found1995 5/8/1995 0.010 0.120 0.020 0.240 0.080 0.960 0.080 0.960 -0.030 -0.360 0.040 0.4801996 5/1/1996 0.030 0.360 0.040 0.480 0.070 0.840 0.080 0.960 0.000 0.000 0.050 0.6001997 5/28/1997 0.020 0.240 0.020 0.240 0.050 0.600 0.060 0.720 -0.020 -0.240 0.050 0.6001998 5/11/1998 0.020 0.240 0.020 0.240 0.050 0.600 0.060 0.720 -0.030 -0.360 0.010 0.1201999 4/26/1999 0.020 0.240 0.030 0.360 0.050 0.600 0.055 0.660 -0.035 -0.420 0.015 0.1802000 6/29/2000 0.025 0.300 0.030 0.360 0.055 0.660 0.055 0.660 -0.030 -0.360 0.015 0.1802001 5/2/2001 0.025 0.300 0.030 0.360 0.050 0.600 0.055 0.660 -0.040 -0.480 0.020 0.2402002 5/21/2002 0.020 0.240 0.030 0.360 0.070 0.840 0.060 0.720 -0.045 -0.540 0.020 0.2402003 5/21/2003 0.025 0.300 0.035 0.420 0.065 0.780 0.060 0.720 -0.040 -0.480 0.015 0.1802004 5/18/2004 0.020 0.240 0.040 0.480 0.070 0.840 0.060 0.720 -0.035 -0.420 0.020 0.2402005 5/31/2005 0.020 0.240 0.040 0.480 0.055 0.660 0.060 0.720 -0.035 -0.420 0.020 0.2402006 5/31/2006 0.020 0.240 0.035 0.420 0.060 0.720 0.060 0.720 -0.035 -0.420 0.010 0.1202007 5/15/2007 0.030 0.360 0.025 0.300 0.055 0.660 0.050 0.600 -0.045 -0.540 0.020 0.2402008 5/27/2008 0.030 0.360 0.025 0.300 0.055 0.660 0.060 0.720 -0.030 -0.360 0.020 0.2402009 6/9/2009 0.015 0.180 0.025 0.300 0.045 0.540 0.060 0.720 -0.030 -0.360 0.020 0.2402010 5/24/2010 0.010 0.120 0.020 0.240 0.060 0.720 0.050 0.600 -0.045 -0.540 0.020 0.240

S-50+00.079

Monument ID →


S-42+00.191

S-60+61.430

S-18+00.234

S-26+00.212

S-3

Notes:(1) Positive values represent downstream displacement (North).(2) Negative values represent upstream displacement (South). IRVINE RANCH WATER DISTRICT Page 1 of 2


NET HORIZONTAL DISPLACEMENT OF SURVEY MONUMENTS1975 THROUGH 2018


Year Date (feet) (inches) (feet) (inches) (feet) (inches) (feet) (inches) (feet) (inches) (feet) (inches)

S-50+00.079

Monument ID →


S-42+00.191

S-60+61.430

S-18+00.234

S-26+00.212

S-3

2011 5/18/2011 0.015 0.180 0.020 0.240 0.060 0.720 0.070 0.840 -0.030 -0.360 0.020 0.2402012 5/18/2012 0.015 0.180 0.025 0.300 0.060 0.720 0.065 0.780 -0.030 -0.360 0.020 0.2402013 6/6/2013 0.015 0.180 0.015 0.180 0.055 0.660 0.060 0.720 -0.035 -0.420 0.015 0.1802014 4/25/2014 0.045 0.540 0.040 0.480 0.080 0.960 0.060 0.720 -0.030 -0.360 0.015 0.1802015 6/4/2015 0.030 0.360 0.020 0.240 0.065 0.780 0.065 0.780 -0.035 -0.420 0.020 0.2402016 7/25/2016 0.030 0.360 0.025 0.300 0.065 0.780 0.070 0.840 -0.025 -0.300 0.015 0.1802017 No survey was done in 20172018 5/31/2018 0.030 0.360 0.030 0.360 0.065 0.780 0.065 0.780 -0.025 -0.300 0.025 0.300

Notes:(1) Positive values represent downstream displacement (North).(2) Negative values represent upstream displacement (South). IRVINE RANCH WATER DISTRICT Page 2 of 2


ELEVATIONS OF SURVEY MONUMENTS1975 THROUGH 2018


S-1 S-2 S-3 S-4 S-6 S-58+00.234 6+00.212 4+00.125 2+00.191 0+61.430 0+00.079

Year Date (feet) (feet) (feet) (feet) (feet) (feet)1975 9/15/1975 200.727 200.956 200.534 200.430 200.570 Initial Reading for S-1 to S-51976 Data were not found1977 Data were not found1978 Data were not found1979 Data were not found1980 Data were not found1981 12/15/1981 200.750 201.970 200.540 200.630 200.5701982 6/15/1982 200.800 201.010 200.570 200.660 200.6101983 Data were not found1984 Data were not found1985 10/20/1985 200.740 200.960 200.540 200.600 200.5501986 Data were not found1987 10/20/1987 200.790 200.550 200.630 200.760 200.550 Initial Reading for S-61988 Data were not found1989 Data were not found1990 Data were not found1991 Data were not found1992 Data were not found1993 Data were not found1994 Data were not found1995 5/8/1995 200.840 201.060 200.610 200.680 200.830 200.6601996 5/1/1996 200.840 201.060 200.610 200.690 200.840 200.6701997 5/28/1997 200.850 201.070 200.610 200.700 200.810 200.6801998 5/11/1998 200.850 201.060 200.600 200.680 200.780 200.6601999 4/26/1999 200.847 201.057 200.592 200.677 200.772 200.6572000 6/29/2000 200.847 201.057 200.597 200.682 200.777 200.6672001 5/2/2001 200.847 201.057 200.602 200.692 200.787 200.6722002 5/21/2002 200.852 201.057 200.597 200.682 200.782 200.6722003 5/21/2003 200.852 201.062 200.602 200.687 200.787 200.6772004 5/18/2004 200.852 201.062 200.602 200.687 200.787 200.6772005 5/31/2005 200.852 201.062 200.602 200.682 200.782 200.6722006 5/31/2006 200.857 201.062 200.597 200.682 200.782 200.6722007 5/15/2007 200.847 201.060 200.597 200.680 200.778 200.6712008 5/27/2008 200.850 201.054 200.591 200.673 200.774 200.6682009 6/9/2009 200.847 201.067 200.607 200.687 200.787 200.6822010 5/24/2010 200.847 201.052 200.587 200.672 200.772 200.667

Comment

Monument ID →Approx. Station →

Note:(1) Elevations are in feet relative to NGVD29 datum. IRVINE RANCH WATER DISTRICT Page 1 of 2


ELEVATIONS OF SURVEY MONUMENTS1975 THROUGH 2018


S-1 S-2 S-3 S-4 S-6 S-58+00.234 6+00.212 4+00.125 2+00.191 0+61.430 0+00.079

Year Date (feet) (feet) (feet) (feet) (feet) (feet) Comment

Monument ID →Approx. Station →

2011 5/18/2011 200.847 201.052 200.592 200.677 200.777 200.6722012 5/18/2012 200.847 201.057 200.592 200.677 200.777 200.6722013 6/6/2013 200.847 201.057 200.587 200.672 200.777 200.6722014 4/25/2014 200.847 201.062 200.597 200.682 200.787 200.6822015 6/4/2015 200.847 201.057 200.587 200.677 200.777 200.6722016 7/25/2016 200.842 201.047 200.582 200.672 200.772 200.6672017 No survey was done in 20172018 5/31/2018 200.847 201.057 200.592 200.682 200.787 200.682

Note:(1) Elevations are in feet relative to NGVD29 datum. IRVINE RANCH WATER DISTRICT Page 2 of 2


NET VERTICAL MOVEMENT OF SURVEY MONUMENTS1975 THROUGH 2018


Year Date (feet) (inches) (feet) (inches) (feet) (inches) (feet) (inches) (feet) (inches) (feet) (inches)1975 9/15/1975 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 Initial Reading for S-1 to S-51976 Data were not found1977 Data were not found1978 Data were not found1979 Data were not found1980 Data were not found1981 12/15/1981 -0.023 -0.276 -1.014 -12.168 -0.006 -0.072 -0.200 -2.400 0.000 0.0001982 6/15/1982 -0.073 -0.876 -0.054 -0.648 -0.036 -0.432 -0.230 -2.760 -0.040 -0.4801983 Data were not found1984 Data were not found1985 10/20/1985 -0.013 -0.156 -0.004 -0.048 -0.006 -0.072 -0.170 -2.040 0.020 0.2401986 Data were not found1987 10/20/1987 -0.063 -0.756 0.000 -0.016 -0.192 -0.200 -2.400 0.000 0.000 0.020 0.240 Initial Reading for S-61988 Data were not found1989 Data were not found1990 Data were not found1991 Data were not found1992 Data were not found1993 Data were not found1994 Data were not found1995 5/8/1995 -0.113 -1.356 -0.104 -1.248 -0.076 -0.912 -0.250 -3.000 -0.070 -0.840 -0.090 -1.0801996 5/1/1996 -0.113 -1.356 -0.104 -1.248 -0.076 -0.912 -0.260 -3.120 -0.080 -0.960 -0.100 -1.2001997 5/28/1997 -0.123 -1.476 -0.114 -1.368 -0.076 -0.912 -0.270 -3.240 -0.050 -0.600 -0.110 -1.3201998 5/11/1998 -0.123 -1.476 -0.104 -1.248 -0.066 -0.792 -0.250 -3.000 -0.020 -0.240 -0.090 -1.0801999 4/26/1999 -0.120 -1.440 -0.101 -1.212 -0.058 -0.696 -0.247 -2.964 -0.012 -0.144 -0.087 -1.0442000 6/29/2000 -0.120 -1.440 -0.101 -1.212 -0.063 -0.756 -0.252 -3.024 -0.017 -0.204 -0.097 -1.1642001 5/2/2001 -0.120 -1.440 -0.101 -1.212 -0.068 -0.816 -0.262 -3.144 -0.027 -0.324 -0.102 -1.2242002 5/21/2002 -0.125 -1.500 -0.101 -1.212 -0.063 -0.756 -0.252 -3.024 -0.022 -0.264 -0.102 -1.2242003 5/21/2003 -0.125 -1.500 -0.106 -1.272 -0.068 -0.816 -0.257 -3.084 -0.027 -0.324 -0.107 -1.2842004 5/18/2004 -0.125 -1.500 -0.106 -1.272 -0.068 -0.816 -0.257 -3.084 -0.027 -0.324 -0.107 -1.2842005 5/31/2005 -0.125 -1.500 -0.106 -1.272 -0.068 -0.816 -0.252 -3.024 -0.022 -0.264 -0.102 -1.2242006 5/31/2006 -0.130 -1.560 -0.106 -1.272 -0.063 -0.756 -0.252 -3.024 -0.022 -0.264 -0.102 -1.2242007 5/15/2007 -0.120 -1.440 -0.104 -1.248 -0.063 -0.756 -0.250 -3.000 -0.018 -0.216 -0.101 -1.2122008 5/27/2008 -0.123 -1.476 -0.098 -1.176 -0.057 -0.684 -0.243 -2.916 -0.014 -0.168 -0.098 -1.1762009 6/9/2009 -0.120 -1.440 -0.111 -1.332 -0.073 -0.876 -0.257 -3.084 -0.027 -0.324 -0.112 -1.3442010 5/24/2010 -0.120 -1.440 -0.096 -1.152 -0.053 -0.636 -0.242 -2.904 -0.012 -0.144 -0.097 -1.164

CommentApprox. Station →Monument ID →

0+61.430S-5

0+00.079S-1

8+00.234S-2

6+00.212S-3

4+00.125S-4

2+00.191S-6

Notes:(1) Positive values represent downward movement (settlement).(2) Negative values represent upward movement (uplift). IRVINE RANCH WATER DISTRICT Page 1 of 2


NET VERTICAL MOVEMENT OF SURVEY MONUMENTS1975 THROUGH 2018


Year Date (feet) (inches) (feet) (inches) (feet) (inches) (feet) (inches) (feet) (inches) (feet) (inches) CommentApprox. Station →Monument ID →

0+61.430S-5

0+00.079S-1

8+00.234S-2

6+00.212S-3

4+00.125S-4

2+00.191S-6

2011 5/18/2011 -0.120 -1.440 -0.096 -1.152 -0.058 -0.696 -0.247 -2.964 -0.017 -0.204 -0.102 -1.2242012 5/18/2012 -0.120 -1.440 -0.101 -1.212 -0.058 -0.696 -0.247 -2.964 -0.017 -0.204 -0.102 -1.2242013 6/6/2013 -0.120 -1.440 -0.101 -1.212 -0.053 -0.636 -0.242 -2.904 -0.017 -0.204 -0.102 -1.2242014 4/25/2014 -0.120 -1.440 -0.106 -1.272 -0.063 -0.756 -0.252 -3.024 -0.027 -0.324 -0.112 -1.3442015 6/4/2015 -0.120 -1.440 -0.101 -1.212 -0.053 -0.636 -0.247 -2.964 -0.017 -0.204 -0.102 -1.2242016 7/25/2016 -0.115 -1.380 -0.091 -1.092 -0.048 -0.576 -0.242 -2.904 -0.012 -0.144 -0.097 -1.1642017 No survey was done in 20172018 5/31/2018 -0.120 -1.440 -0.101 -1.212 -0.058 -0.696 -0.252 -3.024 -0.027 -0.324 -0.112 -1.344

Notes:(1) Positive values represent downward movement (settlement).(2) Negative values represent upward movement (uplift). IRVINE RANCH WATER DISTRICT Page 2 of 2



397B-IRW_Sand Cyn Dam-Annual Rpt 2018_FINAL.doc GENTERRA Consultants, Inc.

FIGURES

Project No. 397B-IRW GENTERRA Consultants, Inc

NGVD29 DATUM IRVINE RANCH WATER DISTRICT FIGURE 4A

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125

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Jan-

17

Feb-

17

Mar

-17

Apr-1

7

May

-17

Jun-

17

Jul-1

7

Aug-

17

Sep-

17

Oct

-17

Nov

-17

Dec

-17

Jan-

18

Feb-

18

Mar

-18

Apr-1

8

May

-18

Jun-

18

Jul-1

8

Aug-

18

Sep-

18

Oct

-18

Nov

-18

Dec

-18

Jan-

19

Res

ervo

ir W

ater

Sur

face

Ele

vatio

n (F

eet)

Piez

omet

er W

ater

Lev

el E

leva

tion

(Fee

t)

SAND CANYON DAM2-YR PIEZOMETER AND RESERVOIR WATER SURFACE ELEVATIONS

PIEZOMETERS P-1A, P-1B, AND P-6 JANUARY 2017 THROUGH DECEMBER 2018

P-1A P-1B P-6 Reservoir

Reservoir

P-1A

P-1B

P-6

Date


NGVD29 DATUM IRVINE RANCH WATER DISTRICT FIGURE 4B

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125

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125

130

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185

190

195

200

205

210

Jan-

17

Feb-

17

Mar

-17

Apr-1

7

May

-17

Jun-

17

Jul-1

7

Aug-

17

Sep-

17

Oct

-17

Nov

-17

Dec

-17

Jan-

18

Feb-

18

Mar

-18

Apr-1

8

May

-18

Jun-

18

Jul-1

8

Aug-

18

Sep-

18

Oct

-18

Nov

-18

Dec

-18

Jan-

19

Res

ervo

ir W

ater

Sur

face

Ele

vatio

n (F

eet)

Piez

omet

er W

ater

Lev

el E

leva

tion

(Fee

t)


PIEZOMETERS P-2A, P-2B, P-5, P-10A, AND P-10BJANUARY 2017 THROUGH DECEMBER 2018

P-2A P-2B P-5 P-10A P-10B Reservoir

Reservoir

P-2A

P-10A

P-2B

Date

P-5

P-10BNotes: (1) P-10A had erroneous reading taken on 5/23/2017.(2) P-2A had erroneous readings taken on 9/27/2018 and 10/24/2018.(3) P-5 had erroneous reading taken on 3/28/2018.

See Note (1)

See Note (2)

See Note (3)


NGVD29 DATUM IRVINE RANCH WATER DISTRICT FIGURE 4C

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190

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205

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Jan-

17

Feb-

17

Mar

-17

Apr-1

7

May

-17

Jun-

17

Jul-1

7

Aug-

17

Sep-

17

Oct

-17

Nov

-17

Dec

-17

Jan-

18

Feb-

18

Mar

-18

Apr-1

8

May

-18

Jun-

18

Jul-1

8

Aug-

18

Sep-

18

Oct

-18

Nov

-18

Dec

-18

Jan-

19

Res

ervo

ir W

ater

Sur

face

Ele

vatio

n (F

eet)

Piez

omet

er W

ater

Lev

el E

leva

tion

(Fee

t)


PIEZOMETERS P-4, P-8A, P-8B, P-9A, P-9B, AND P-11JANUARY 2017 THROUGH DECEMBER 2018

P-4 P-8A P-8B P-9A P-9B P-11 Reservoir

Reservoir

P-8A

P-9A

Date

P-4P-9B

P-8BP-11

Erroneous

Notes: (1) P-11 had erroneous readings taken on 10/26/2017 and 6/28/2018.(2) P-9A had erroneous readings taken on 5/30/2018 and 7/26/2018.

Erroneous

Erroneous


NGVD29 DATUM IRVINE RANCH WATER DISTRICT FIGURE 4D

120

125

130

135

140

145

150

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175

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185

190

195

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205

210

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125

130

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155

160

165

170

175

180

185

190

195

200

205

210

Jan-

17

Feb-

17

Mar

-17

Apr-1

7

May

-17

Jun-

17

Jul-1

7

Aug-

17

Sep-

17

Oct

-17

Nov

-17

Dec

-17

Jan-

18

Feb-

18

Mar

-18

Apr-1

8

May

-18

Jun-

18

Jul-1

8

Aug-

18

Sep-

18

Oct

-18

Nov

-18

Dec

-18

Jan-

19

Res

ervo

ir W

ater

Sur

face

Ele

vatio

n (F

eet)

Piez

omet

er W

ater

Lev

el E

leva

tion

(Fee

t)


PIEZOMETERS P-3 AND P-7JANUARY 2017 THROUGH DECEMBER 2018

P-3 P-7 Reservoir

Reservoir

P-3

P-7

Date


NGVD29 DATUM IRVINE RANCH WATER DISTRICT FIGURE 4E

120

125

130

135

140

145

150

155

160

165

170

175

180

185

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195

200

205

210

120

125

130

135

140

145

150

155

160

165

170

175

180

185

190

195

200

205

210

Jan-

17

Feb-

17

Mar

-17

Apr-1

7

May

-17

Jun-

17

Jul-1

7

Aug-

17

Sep-

17

Oct

-17

Nov

-17

Dec

-17

Jan-

18

Feb-

18

Mar

-18

Apr-1

8

May

-18

Jun-

18

Jul-1

8

Aug-

18

Sep-

18

Oct

-18

Nov

-18

Dec

-18

Jan-

19

Res

ervo

ir W

ater

Sur

face

Ele

vatio

n (F

eet)

Piez

omet

er W

ater

Lev

el E

leva

tion

(Fee

t)



P-12 P-13 Reservoir

Reservoir

P-12

P-13

Date


NGVD29 DATUM IRVINE RANCH WATER DISTRICT FIGURE 5A

120

125

130

135

140

145

150

155

160

165

170

175

180

185

190

195

200

205

210

120

125

130

135

140

145

150

155

160

165

170

175

180

185

190

195

200

205

210

Jan-

09

Jul-0

9

Jan-

10

Jul-1

0

Jan-

11

Jul-1

1

Jan-

12

Jul-1

2

Jan-

13

Jul-1

3

Jan-

14

Jul-1

4

Jan-

15

Jul-1

5

Jan-

16

Jul-1

6

Jan-

17

Jul-1

7

Jan-

18

Jul-1

8

Jan-

19

Res

ervo

ir W

ater

Sur

face

Ele

vatio

n (F

eet)

Piez

omet

er W

ater

Lev

el E

leva

tion

(Fee

t)

SAND CANYON DAM10-YR HISTORICAL PIEZOMETER AND RESERVOIR WATER SURFACE ELEVATIONS

PIEZOMETERS P-1A, P-1B, AND P-6 JANUARY 2009 THROUGH DECEMBER 2018

P-1A P-1B P-6 Reservoir

Reservoir

P-1A

P-1B

P-6

Date

Note: (1) P-1A had an erroneous reading below the tip elevation on 6/28/2016.

See Note (1)


NGVD29 DATUM IRVINE RANCH WATER DISTRICT FIGURE 5B

120

125

130

135

140

145

150

155

160

165

170

175

180

185

190

195

200

205

210

120

125

130

135

140

145

150

155

160

165

170

175

180

185

190

195

200

205

210

Jan-

09

Jul-0

9

Jan-

10

Jul-1

0

Jan-

11

Jul-1

1

Jan-

12

Jul-1

2

Jan-

13

Jul-1

3

Jan-

14

Jul-1

4

Jan-

15

Jul-1

5

Jan-

16

Jul-1

6

Jan-

17

Jul-1

7

Jan-

18

Jul-1

8

Jan-

19

Res

ervo

ir W

ater

Sur

face

Ele

vatio

n (F

eet)

Piez

omet

er W

ater

Lev

el E

leva

tion

(Fee

t)


PIEZOMETERS P-2A, P-2B, P-5, P-10A, AND P-10BJANUARY 2009 THROUGH DECEMBER 2018

P-2A P-2B P-5 P-10A P-10B Reservoir

Reservoir

P-2A

P-10A

P-2B

Date

P-5

P-10B

Notes: (1) Vibrating wires were installed in December 2015 for P-9A to P-13.(2) Vibrating wires were not logging in November 2016 for P-9A to P-13.(3) P-2A had erroneous readings taken on 4/4/2010, 9/27/2018, and 10/24/2018.(4) P-5 had erroneous reading taken on 3/28/2018.

See Note (3)

See Note (6) See Note (5)

(5) P-10A had erroneous reading taken on 5/23/2017.(6) P-10B had possibly erroneous readings taken on

10/29/2013, 8/26/2014, 3/26/2015, 4/29/2015, 8/26/2015, and 11/24/2015.

See Note (4)

See Note (3)


NGVD29 DATUM IRVINE RANCH WATER DISTRICT FIGURE 5C

120

125

130

135

140

145

150

155

160

165

170

175

180

185

190

195

200

205

210

120

125

130

135

140

145

150

155

160

165

170

175

180

185

190

195

200

205

210

Jan-

09

Jul-0

9

Jan-

10

Jul-1

0

Jan-

11

Jul-1

1

Jan-

12

Jul-1

2

Jan-

13

Jul-1

3

Jan-

14

Jul-1

4

Jan-

15

Jul-1

5

Jan-

16

Jul-1

6

Jan-

17

Jul-1

7

Jan-

18

Jul-1

8

Jan-

19

Res

ervo

ir W

ater

Sur

face

Ele

vatio

n (F

eet)

Piez

omet

er W

ater

Lev

el E

leva

tion

(Fee

t)


PIEZOMETERS P-4, P-8A, P-8B, P-9A, P-9B, AND P-11JANUARY 2009 THROUGH DECEMBER 2018

P-4 P-8A P-8B P-9A P-9B P-11 Reservoir

Reservoir

P-8A

P-9A

Date

P-4

P-9BP-8B P-11

Rise following rainfall event

Erroneous

Notes: (1) Vibrating wires were installed in December 2015 for P-9A to P-13.(2) Vibrating wires were not logging in November 2016 for P-9A to P-13.(3) P-9A had erroneous readings taken on 5/30/2018 and 7/26/2018.(4) P-9B had an erroneous reading on 8/26/2014.(5) P-11 had erroneous readings below tip elevation taken on 10/26/2017

and 6/28/2018.

Erroneous

Erroneous


NGVD29 DATUM IRVINE RANCH WATER DISTRICT FIGURE 5D

120

125

130

135

140

145

150

155

160

165

170

175

180

185

190

195

200

205

210

120

125

130

135

140

145

150

155

160

165

170

175

180

185

190

195

200

205

210

Jan-

09

Jul-0

9

Jan-

10

Jul-1

0

Jan-

11

Jul-1

1

Jan-

12

Jul-1

2

Jan-

13

Jul-1

3

Jan-

14

Jul-1

4

Jan-

15

Jul-1

5

Jan-

16

Jul-1

6

Jan-

17

Jul-1

7

Jan-

18

Jul-1

8

Jan-

19

Res

ervo

ir W

ater

Sur

face

Ele

vatio

n (F

eet)

Piez

omet

er W

ater

Lev

el E

leva

tion

(Fee

t)



P-3 P-7 Reservoir

Reservoir

P-3

P-7

Date

Erroneous

Notes: (1) P-3 had an erroneous reading taken on 9/28/2011.


NGVD29 DATUM IRVINE RANCH WATER DISTRICT FIGURE 5E

120

125

130

135

140

145

150

155

160

165

170

175

180

185

190

195

200

205

210

120

125

130

135

140

145

150

155

160

165

170

175

180

185

190

195

200

205

210

Jan-

09

Jul-0

9

Jan-

10

Jul-1

0

Jan-

11

Jul-1

1

Jan-

12

Jul-1

2

Jan-

13

Jul-1

3

Jan-

14

Jul-1

4

Jan-

15

Jul-1

5

Jan-

16

Jul-1

6

Jan-

17

Jul-1

7

Jan-

18

Jul-1

8

Jan-

19

Res

ervo

ir W

ater

Sur

face

Ele

vatio

n (F

eet)

Piez

omet

er W

ater

Lev

el E

leva

tion

(Fee

t)



P-12 P-13 Reservoir

Reservoir

P-12

P-13

Date

Notes: (1) Vibrating wires were installed in December 2015 for P-9A to P-13.(2) Vibrating wires were not logging in November 2016 for P-9A to P-13.(3) P-12 had an erroneous "dry" reading on 10/26/2010.(4) P-12 had an erroneous reading below tip elevation on 8/29/2012.

See Note (3) See Note (4)

Project No. 397B-IRW GENTERRA Consultants, Inc.

NGVD29 DATUM IRVINE RANCH WATER DISTRICT FIGURE 6

100

105

110

115

120

125

130

135

140

145

150

155

160

165

170

175

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185

190

195

200

205

210

-0.4

-0.2

0.0

0.2

0.4

0.6

0.8

1.0

1.2

1.4

1.6

1.8

2.0

2.2

2.4

2.6

2.8

3.0

3.2

3.4

3.6

3.8

4.0

Jan-

17

Feb-

17

Mar

-17

Apr-1

7

May

-17

Jun-

17

Jul-1

7

Aug-

17

Sep-

17

Oct

-17

Nov

-17

Dec

-17

Jan-

18

Feb-

18

Mar

-18

Apr-1

8

May

-18

Jun-

18

Jul-1

8

Aug-

18

Sep-

18

Oct

-18

Nov

-18

Dec

-18

Jan-

19

Res

ervo

ir W

ater

Sur

face

Ele

vatio

n (F

eet)

Seep

age

Flow

Rat

e (G

allo

ns/M

inut

e)

SAND CANYON DAM 2-YR SEEPAGE FLOW RATES AND RESERVOIR WATER SURFACE ELEVATIONS

JANUARY 2017 THROUGH DECEMBER 2018Left Subdrain Right Subdrain Reservoir Spillway Crest

Reservoir

Left Subdrain

Right Subdrain

Date

Spillway Crest

Project No. 397B-IRW GENTERRA Consultants, Inc.

NGVD29 DATUM IRVINE RANCH WATER DISTRICT FIGURE 7

100

105

110

115

120

125

130

135

140

145

150

155

160

165

170

175

180

185

190

195

200

205

210

-0.4

-0.2

0.0

0.2

0.4

0.6

0.8

1.0

1.2

1.4

1.6

1.8

2.0

2.2

2.4

2.6

2.8

3.0

3.2

3.4

3.6

3.8

4.0

Jan-

09

Jul-0

9

Jan-

10

Jul-1

0

Jan-

11

Jul-1

1

Jan-

12

Jul-1

2

Jan-

13

Jul-1

3

Jan-

14

Jul-1

4

Jan-

15

Jul-1

5

Jan-

16

Jul-1

6

Jan-

17

Jul-1

7

Jan-

18

Jul-1

8

Jan-

19

Res

ervo

ir W

ater

Sur

face

Ele

vatio

n (F

eet)

Seep

age

Flow

Rat

e (G

allo

ns/M

inut

e)

SAND CANYON DAM 10-YR HISTORICAL SEEPAGE FLOW RATES AND RESERVOIR WATER SURFACE ELEVATIONS

JANUARY 2009 THROUGH DECEMBER 2018

Left Subdrain Right Subdrain Reservoir Spillway Crest

Reservoir

Left Subdrain

Right Subdrain

Left Subdrain blocked by roots and soil in March of 2016. Blockage subsequently cleared and pipe repaired by District.

Date

Spillway Crest


IRVINE RANCH WATER DISTRICT FIGURE 8

-0.10

-0.09

-0.08

-0.07

-0.06

-0.05

-0.04

-0.03

-0.02

-0.01

0.00

0.01

0.02

0.03

0.04

0.05

0.06

0.07

0.08

0.09

0.10

Jan-

95

Jan-

96

Jan-

97

Jan-

98

Jan-

99

Jan-

00

Jan-

01

Jan-

02

Jan-

03

Jan-

04

Jan-

05

Jan-

06

Jan-

07

Jan-

08

Jan-

09

Jan-

10

Jan-

11

Jan-

12

Jan-

13

Jan-

14

Jan-

15

Jan-

16

Jan-

17

Jan-

18

Jan-

19

Hor

izon

tal D

ispl

acem

ent S

ince

Initi

al S

urve

y (F

eet)

SAND CANYON DAM24-YR HISTORICAL NET HORIZONTAL DISPLACEMENT

SURVEY MONUMENTS S-1 THROUGH S-6JANUARY 1995 THROUGH DECEMBER 2018

S-1 S-2 S-3 S-4 S-5 S-6

S-1

Date

S-2

S-3S-4

S-5

S-6

Dow

nstre

am (N

orth

)U

pstre

am (S

outh

)


IRVINE RANCH WATER DISTRICT FIGURE 9

-0.30

-0.28

-0.26

-0.24

-0.22

-0.20

-0.18

-0.16

-0.14

-0.12

-0.10

-0.08

-0.06

-0.04

-0.02

0.00

0.02

0.04

0.06

0.08

0.10

Jan-

95

Jan-

96

Jan-

97

Jan-

98

Jan-

99

Jan-

00

Jan-

01

Jan-

02

Jan-

03

Jan-

04

Jan-

05

Jan-

06

Jan-

07

Jan-

08

Jan-

09

Jan-

10

Jan-

11

Jan-

12

Jan-

13

Jan-

14

Jan-

15

Jan-

16

Jan-

17

Jan-

18

Jan-

19

Vert

ical

Mov

emen

t Sin

ce In

itial

Sur

vey

(Fee

t)

SAND CANYON DAM24-YR HISTORICAL NET VERTICAL MOVEMENT

SURVEY MONUMENTS S-1 THROUGH S-6JANUARY 1995 THROUGH DECEMBER 2018

S-1 S-2 S-3 S-4 S-5 S-6

S-1

Date

S-2

S-3

S-4

S-5

S-6

Dow

nwar

d (S

ettle

men

t)U

pwar

d (U

plift

)

annual surveillance report january 2018 through … safety...annual surveillance report january 2018...

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